Search

To see this working, head to your live site. Categories All Posts My Posts Login / Sign up Shape Exchange Forum Get in touch with the Shape user community. Ask questions or reply to those of others. Show your science or fun results. Create New Post General Questions Ask about the science that can be done with Shape. Need help with the modeling strategy? Here is the place to ask. Views Posts 3 Follow Workflow What is a good way to achieve may goal?Done this, what´s next? Questions on how to get into the flow ... Views Posts 0 Follow Please, show me how to ... Tutorials and more from you and your peers. Views Posts 0 Follow 3-D Module Tips and tricks all around the 3-D Module. Did you find a curious way to do something? Share it here. Views Posts 0 Follow Render Module Having ideas or questions on the Render Module? Something doesn´t look as you expected? Talk or ask about it here. Views Posts 0 Follow Bug Reports Found something that isn´t right in Shape? Please, report any bugs here. We will check it out and fix it asap. Views Posts 3 Follow New Posts vazquez Sep 01 Hi Nico & Wolfgang, Recently my iMac couldn't read a shp file built in Ubuntu. However, Ubuntu can read my shp files built in iMac. Help pls Bug Reports 3 comments 3 0 mark.rawlings Jan 03 Free rotation of the "Render" pane in the 3D Module? General Questions In the ShapeScience training videos on YouTube, it appears trivial in the 3D Module to freely rotate the Render pane wireframe view (in the same way as in the "Free-Form" pane), but I can't seem to figure out how to do it on my Mac. The only way I've found to change the view of the Render pane is to right-click in the pane & use the contextual menu to manually enter a specified set of rotation numbers for each axis. 0 comments 0 0 mark.rawlings Jan 03 Custom Density Profile Editing on a Mac? General Questions When editing a Custom Density profile of an object, how does the user actually manipulate the Control Points when using a Mac? Control-clicking on a Mac always seems to be the same as right-clicking, which brings up the contextual menu instead. None of the other Mac modifier keys obviously seem to work for this, either. 0 comments 0 0 Forum - Frameless

Downloads The most up-to-date installers for Window, Mac OSX and Linux can be found found at: Installers Updates ​ Occasionally, updates will be issues without supplying new installers. This greatly reduces the size of the downloaded needed. The update packages will contain library files that simply need to be copied over the files that already exist on your system (whever you have installed ShapeX). Notes: ​ Since the last release, Shape has been revamped almost completely. In particular, the user interface (UI) and the rendering algorithms have seen profound changes. New modules and modifiers help with the workflow New manual & website help the user to get started User forum - ask questions, share tips & tricks, propose features Installers for Windows, MacOSX, Linux RPM & Debian ​ IMPORTANT NOTE: Remember that to take full advantage of your computers RAM, you need to manually set it in the ShapeX.cfg file. Search for this file within the installation directory. Open it with Administrator privileges and add the minimum and maximum RAM that you will allow Shape to use, say e.g. 14 GB of your actual RAM of 16 GB. Edit the .cfg file in a text editor with the following lines: [JVMOptions] -Xms1000m -Xmx14000m ​ Make sure that there are no spaces before or behind the lines with the numbers. Save the file and run Shape. At the bottom of the UI the "Total (Mb): " should now indicate approximately 1.4E4 .

Export Module Overview ​ The Export Module exports the 3-D model into various output formats that can then be used as data for external use. It was mainly designed to prepare models for export to the iluvia software for external interactive visualization. ​ The Export Module uses data from an intermediate output of Shape that contains all the radiation information within a cubic grid with uniform voxels. The name and disk folder in which this intermediate file is located are set in the Output tab of the Render Module . Exporting Shape models into new formats for external visualization may be a challenge. This is due to the fact that in Shape you may can use a variety of physical radiation effects, some of which can not be directly mapped to the simpler treatment of emission and opacity in interactive graphics software that rely on ARGB color coding or similar. General Workflow: In the Output tab of the Render Module, make sure there is a valid filename and path provided. The output will be with the extension .ilv . This file is loaded into the Export Module. Then a previsualization is generated by adjusting the parameters on the left and right side of the preview image in the middle. The parameters on the left adjust the behavior on the level of the voxels of the input grid. Those on the left adjust the visualization on the image plane after the preview rendering. The preview attempts to recreate the view of a GPU rendering by simulating a similar shader. It also allows you relatively quick interactive inspection. For low resolution you can interactive rotate the object for inspection. Parameter Panels: Volume: The parameters on the left side of the preview control the values of voxel data cube before it is previewed and converted to a different data format. Note that scaling and clamping these values in the presence of opacity maybe result in non-linear behavior that sometimes is not intuitiv. In combination with the parameters on the output side (Preview parameters), it may require some trial and error to obtain the expected result. ​ Filename: Select the .ilv input file to be used for exporting to an external file format. Click on the icon on to the right of the text box to open the file system dialog and choose a file from disk. ​ Reload: If the content of the input file has been updated and the filename remains the same, use the Reload Button to load the new content. Size: Shows the width of the cube by the number of voxels along one side. ​ Downsample: If the original .ilv file is too large, it can be downsampled x2 in terms of side length by clicking on this button. ​ Intensity range: The range of voxel intensities. ​ Histogram: The histogram of the voxel intensity values opens when this button is clicked. ​ Opacity range: The range of opacity values is shown. ​ Histogram: Shows the histogram of the voxel opacity values when this button is clicked. ​ Intensity scale: Scale all voxel intensities by this factor. ​ Opacity scale: Scale all voxel opacity values by this factor. Max Intensity: Set the value of the maximum intensity. All higher values of voxel intensity are clamped to this value. If the default value of -1 is set, then the maximum value of all voxels is automatically used. ​ Max Opacity: Set the value of the maximum opacity. All higher values of voxel opacity are clamped to this value. If the default value of -1 is set, then the maximum value of all voxels is automatically used.} ​ Show stars: This flag switches on any stars that might be saved in a file that has the same base name as the .ilv file. ​ Show volume: Shows the volume save in the .ilv file. ​ Show cube: Show a line cube that delineates the space domain of the .ilv file. ​ Preview: The Preview parameters to the right side of the preview image window control the preview in the output format. It allows you relatively quick interactive inspection. For low resolution you can interactive rotate the object for inspection. Image size: The preview image resolution in pixels. Lower resolution allows for a faster and more interactive preview. ​ I factor: Intensity factor to be applied to the preview at the image level. Star factor: A scaling factor for the brightness of the stars. ​ A factor: A scaling factor for the opacity. ​ Camera: ​ X, Y, Z rot: The rotation angles of the preview camera around the cartesian coordinate axes (in degrees). ​ X, Y, Z pos: The shifted position of the preview camera around the cartesian coordinate axes in units of the width of the domain (0-1). ​ Zoom: Camera distance from the center in units of the width of the domain. ​ Reset Camera: Set the camera values back to the defaults. ​ Statistics: Shows the Maximum value of the preview image. It is convenient to adjust this to values near 1. Export: Format: Various output formats can be chosen. Most importantly, the DDS format is a standard format that encapsulates slices of the data cube in ABGR image format, that can then be imported in external volume visualization software. This is also the format for the iluvia software that is developed by ilumbra.com where you can fully interactively view your models. The Volume option, is a .ilv file with properties that correspond to the transformation that the Export Module made to the original. ​ The PNG option outputs a sequence of slices of the volume in standard PNG image format including absorption. The slices are in the XY plane and change along the Z-axis of the World Coordinate System. ​ Directory: Select the directory on disk where to output the exported file. Omit empty: When selected, the slices where the emission and opacity are both zero will be omitted from the output. This may save data and may reduce the load on the visualization system that will process the output data. ​ Crop: . When activated, the output will be cropped to a size of Crop size. This is useful for models in which for some reason the domain is significantly larger than the content. ​ Export: Start the export process. ​ ​

Key Sub-S ystem: The Modifier Stack A model in Shape is build starting from a few basic mesh objects such as spheres, cylinders, tori or imported ones. ​ Very few objects have such regular structure, however, and the fundamental purpose of Shape is to enable the user to reproduce any structure the universe comes up with at us as closely as possible. There these "primitives" have to be "modified". That is why the operators in Shape are called modifiers . Since there is a large variety of modifiers, the are assembled in a modifier stack (see the image on the right). This list of modifiers operates on the primitive mesh in sequence from the top to bottom. ​ It is very important to note that for some operator combinations, such as rotations, the order in which they are applied makes a difference. ​ When a new modifier is added from the drop-down list that opens by clicking on the plus (+) sign below the stack, it is added to the bottom of the list. They can be reordered by dragging and dropping them into the desired position. To delete one or more modifiers select them in the stack and then click on the "x" at the bottom of the stack. ​ For good practice we recommend to order the modifiers by type as long as the order can be chosen without affecting the result. Modifier that apply to physical quantities such as density and temperature should go at the top, as shown in the example. Copy-Paste modifiers: ​ ​ ​ Modifiers can be copied within the same stack or to the stack of a different object. To copy the modifier to the buffer click on the Copy icon at the bottom of the stack. Then click on the paste button right beside to paste it to the same object. ​ To paste the modifier to a different object, select the target object and click on the paste button. When you do that, a small pop-up window opens with two option to select from. You can paste the modifier as a "new copy " or as an "instance ". The new copy of the modifier will act independently of the original. The instance of the original will work in unison with the original. This means that changes in the parameters of one instance will be automatically transferred to the other. You can have several instanced copies of the same modifier, thereby saving time by changing only one of them to affect all the others in the same way. This is an easy way to maintain the same structure for several meshes or other features of an object. ​ Modifiers: ​ There are basically three categories of modifiers: physical, geometry and transform . In the modifier stack these are identified by having a green, orange and white background respectively. The physical modifiers act on the local physical properties that determined the interaction of the gas with the radiation. Examples are the density, temperature, velocity or boost and points . The geometry modifiers move the vertices of the mesh to turn the primitive starter shapes into more complex structures. Examples for these are the bump, squeeze, twist and size modifiers. These modifiers do not move the origin of the local coordinate system. ​ Contrary to the geometry modifiers, the transform modifiers precisely do move the local coordinate center . The physical and geometry modifiers then take the new local coordinate center as a reference. ​ Links to descriptions of each modifier can be found in the Index . ​ ​ ​ ​ ​ ​

Key Sub-S ystem: Coordinate Systems There are several coordinate systems defined in Shape. First of all in most contexts the coordinates may be defined in Cartesian, Spherical or Cylindrical coordinates. ​ Note that for the spherical coordinates the label convention is that of the North America, with q being longitude and f the latitude. ​ Hierarchy of coordinate systems: ​ In addition to the types of coordinate system, there is a hierarchy that determines the origin and orientation of the coordinates. ​ First there is the global "world" coordinate system that is fixed and everything else is embedded in this system. ​ The orientation of the world coordinate system is show by the colored coordinate axes in the lower left corner of the 3D views in the 3D Module (see images on the right). Note that it is not centered on the center of the coordinate system and only provides a visual cue of the orientation. The colors of the xyz axes follow the common order of the color channels rgb (red, green, blue), respectively. ​ Every object has its own "local" coordinate system , that may move around in the world coordinate system depending on the types of modifier that are applied. ​ As an illustration compare the two images on the right. In the first one the spherical mesh and the density distribution are centered on the world coordinate system. No changes have been made to any positions. In the second example a Translation Modifier has been applied. It moves the mesh away from the World Origin. Not only the mesh is moved but the density distribution goes along. Similarly, the Rotation Modifier will rotate the density structures along with the mesh, since thee local coordinate system changes . ​ The translation, rotation and scale operations can be interactively handled using the corresponding Move, Rotate and Size tools in the System tab that is located to the left of teh 3-D views. It is important to note that, contrary to the Translation and Rotation modifiers, the Size tool and Modifier does NOT change the scaling of the local coordinate system. This would cause too many practical problem during modeling. It only changes the mesh. This is similar to the Displacement modifier which only moves the mesh, not the coordinate system. For rotating only the mesh, operators such as the Twist modifier can be applied. ​ In third place there is the "widget" coordinate system that is applied to some modifiers. They often need to be centered at different positions within an object, which can be achieved by moving and rotating the coordinate system of the modifier using the Widget tool or Widget dialog . Different modifiers have independent widget coordinate systems. By default modifiers follow the local coordinate system , meaning that their widget coordinates are coincident with the local system until the widgets themselves are changed. ​ ​ ​ ​ But the coordinate center that a modifier refers to can be changed by changing the widget either interactively with the Widget tool or numerically by opening the Widget dialog from within the modifier panel. To open the Widget dialog click on the Widget Edit button at the bottom of the modifier panel. ​ ​ In the image on the right under the widget dialog the object mesh remains at the world origin, while the density distribution is off-center at the position of the widget . The widget itself is represented by arrows. Each modifier may have independent widget, i.e. local coordinate system positions. ​ In the following image shows the application of the Displacement modifier , which moves only the mesh , not the coordinate system. The mesh container changed position, but the density distribution remained centered on the world coordinates. ​ ​ An additional fourth coordinate system is that of the observer or camera . These are the coordinates seen in the "shape view port" of the 3D Module and the rendered image in the Rendering Module . ​ ​ OPERATOR ORDER MATTERS! In the modifier stack several rotations, translations and other operators can be applied one after the other. The result of such combined operations, in general, strongly depends on the order in which they are executed. Therefore the order of the operator in the modifier stack is very important. For instance, translation can be combined in any order (they are commutative ), rotations among themselves and rotations together with translations can not. ​ ​ Coordinate Display Options Dialog: ​ The Options Dialog that opens by clicking on the wrench icon on the menu bar of the 3D Module allows you to customize the display of a Cartesian coordinate mesh within the 3D views. It can helps as a reference during the modeling process. An example is show in the bottom image in the column on the right. A little experimentation should clarify the meaning and effect of the various parameters. ​

They are a key functionality in ShapeX the usage of which should be mastered in order to create the most realistic models. ​ Modifiers determine the properties of the objects as a function of position in space, hence it is important to know as much as possible about coordinate systems in general (Spherical, Cartesian & Cylindrical) and how they are used in ShapeX. See Coordinate Systems for more information on this topic. Modifiers are assigned to an object in the form of a list or Modifier Stack . This list of operators is executed on the object from the top to the bottom. For many of the modifiers the order in which they are executed does not matter. However, some operators, e.g. those that globally or locally involve some form of rotation, need to be stacked in the right order to produce the desired result. It is therefore important to know whether they order can be reversed or not. Knowledge about commutative properties of operators, or sufficient experimentation, is useful here. Modifiers Overview Modifiers are a operators in the 3-D module that allow you to add or change, i.e. modify properties of an object in the scene. There are different types of modifiers, some change the geometry of the mesh objects, others assign scalar or vector type physical properties such as density or velocity, respectively. After adding or selecting a particular modifiers, its Properties are displayed under the Modifier Stack . These can then be edited either by changing parameter value fields or after opening additional dialogs or graphs. ​ Adding or deleting modifiers is done using the blue + and the red x sign, respectively. When you select a modifier you can move it up and down in the stack with the green arrows. More than one modifier of the same type can be applied with different coordinate systems. In some cases you might have to change the Operation setting from Replace to either Add or Scale , otherwise the last modifier of this type replaces all previous ones. Using combinations of the same type of modifiers allows a larger variety of structures to be build. ​ Modifiers can also be copied and pasted with the corresponding buttons. When you use the paste button, a small dialog will open that asks you to decide whether the modifier should be a copy or and instance of the original modifier. When you choose copy then the new modifier will be completely independent from the other. However, and instanced modifier will always change together with its original and vice versa. Instanced modifiers are a great tool to provide the same parameters for more than one object, while only needing to change a single one of them. Types of Modifiers Physical Modifiers ​ Physical modifiers add or change physical properties as a function of position. They include the Density , Temperature , Pressure , Image Texture , Taper , Velocity, GField and BField . The Boost modifier is a helper modifier to the scalar physical modifiers and is used to change those quantities, but depending on the geometry of another mesh object. This is useful, for instance, to reduce or cut out part of the density of one object using another. Geometry Modifiers ​ Geometry modifiers change the structure of the polygon mesh. They include Bump, Curvature, Displacement, Image Displacement , Projection, Random, Sculpt, Shear, Shell, Size, Spiral, Squeeze, Squish, Stretch, Texture Displacement, Twist, Universal, and Warp . ​ The geometry modifiers move the vertices of a polygon mesh within the local coordinate system of an object. If you move or rotate the local coordinate system with a Rotation or Translate modifier, then the geometry modifiers act in the transformed coordinate system. Note that the Displacement modifier is a geometry modifier and moves only the vertices, but not the origin of the local coordinate system is does the Translate modifier. This is useful when you want to move a complete object, such as a small sphere within a fixed coordinate system and apply, for instance, the Velocity or Density modifiers in the original coordinate system. ​ Modifier Parameter Panel: Common Parameters ​ The parameters that modifiers take vary considerably. They are described in the sections for individual modifiers. ​ What they have in common are the Name field and the Enabled flag . In the Name field you can set a name for this particular modifier, which is strongly recommended, since it allows one to easily identify a modifier, which becomes more and more important once the number of modifiers increases for a particular object or for the project itself. It is especially important once the Modifier Module is used to manage a large number of modifiers. ​ As the name implies, the Enabled flag allows one to enable or disable a particular modifier. ​ Modifier Module: The Modifier Module becomes important once a model contains a large number of objects and modifiers. Often different objects have similar basically the same modifiers that have at least some parameters in common. If they are not instances of each other or have their parameters organized as global variables, the Modifier Module allows you to select a number of modifiers and change their parameters in a single operation. It also provides a good way to get an overview of which modifiers are used by which objects as well as the possibility to sort them by type. For more details on the Modifier Module go to its more detailed description in its own section of this manual.

Modifiers The Image Texture Modifier ​uses an grey-scale image to control density or other physical properties as a function of the image pixel intensity. It is similar to the Image Displacement Modifier (IDM) . Refer to the page of the IDM for details. Here we will describe only the differences to the IDM. This allows one to use actual images to influence them model density distribution. As shown in the example on the right, a potential application is in the modelling of spiral galaxies, where we also made use of the IDM with the same base image. The Image Texture Modifier (ITM) was used to better define the density and brightness structure in addition to the overall shape produced by the IDM. The ITM "projects" the density distribution given by the image along the direction of and starting at the position of the Gizmo through the mesh. If not modulated by other modifiers, the ITM produces a constant density along the direction of projection. For a more realistic distribution it should be further processed in that direction using, e.g. the Taper Modifier. Parameters: ​ Name: If multiple Modifiers are used, make sure to name them adequately for ease of identification. ​ Enabled: When deselected, the modifier will not be applied. ​ Variable: Select the physical variable on which the ITM shall operate. ​ Operation: Select the operation the ITM shall perform on the physical variable. ​ Radial: Select this option if you wish the displacement to be radial from the origin of the Local Coordinate System of the mesh. ​ Filename: Click on the button on the right to open the file selection dialog to open the image file to be used to the ITM. The filename will be displayed in the text field. ​ Width & Height: The full size of the image in the 3-D Module in local x & y directions. Magnitude: Set up the how the mesh displacement shall be as a function of the pixel brightness of the image assuming that it has an interval from x=(0-1) for greyscale values of (0-255). You can use an analytic function of x (the pixel value between 0 and 1) or a corresponding point function. Widget: Opens the Widget panel shown on the right and enables the preview of the displacement image that helps to place it correctly. To see the preview image, the Display has to be enabled and the object needs to be selected in the object tree. The not only the Widget arrows are show, but also the preview image as shown below the Widget panel on the right. ​ Auto Update: If you change the image texture using an external software such as Gimp or Photoshop, then you can enable the automatic loading of the image by clicking on Start. Make sure to Stop it again after you finish. Since the image is read from disk, you need to save it after every change you want to be updated in Shape. ​ Interval (ms): The the interval between Updates of the image from disk. ​ Modifiers: Image Texture

Introduction Why Shape? ​ Images inspire us. Images lead to ideas. We made Shape as a tool to test inspirations. Play True or False. By finding out whether an idea works or not, either way, with Shape you can find new insight into nature for yourself and others. ​ 3-D visualizations of astrophysical objects and phenomena in science and the media are often made with non-scientific software or the result is too abstract most of the time. Shape combines both worlds, putting as much computational astrophysics as possible to the service of research and outreach. ​ Whether you are looking for profound scientific insight or photorealistic volumetric visualizations of what is going in the universe around us. the odds are you are in the right place. What makes Shape different? ​ We want Shape to be easy to handle and fast to learn, so you can quickly play with the results and change things, before an inspiration evaporates. Shape is different from other astrophysical modeling tools, since it is based on modern interactive 3-D modeling technology similar to the one used for special effects, video games and architectural visualization. We combined this technology with custom made rendering, visualization and plotting techniques drawn from numerical astrophysics. ​ Shape allows you to build astrophysical structures and processes in a controlled way from very simple structures to highly complex environments. They can either be static or variable and are build either from polygon meshes, hydrodynamic simulations or a combination of both. The combination of hydrodynamic models with polygon mesh objects in astrophysics is a unique feature of Shape. Shape continuously evolves, following the users' ideas and needs. It is interactive and the physics is highly customizable through the interface and, make sure to note: all this without the need for programming by the user .

The Texture Displacement Modifier uses a procedural texture to deform a mesh. The value of the 3-D texture at position of a mesh vertex in space determines how far the vertex is pushed away from its original position. The magnitude of the position change of the vertex as a function of the grey value of the texture. The direction can be chosen to be radial (set the radial flag) from the local coordinate system or you can use the widget to set the direction. The Magnitude dialog: In the Magnitude dialog you set the function that determines the distance a vertex is pushed based on the grey-scale value of the texture at its original position in space. The values of the texture is in the range [0,1]. The variable that carries these values is "x". So, if you use the default "x" as a function, the vertices will move between 0 and 1 units. The example mesh show in the figure below uses a "clumpy" texture with a few hundred clumps distributed in the spatial domain. The function that is used as magnitude of the displacement is 15*(x-0.5). The reason we subtract 0.5 from x is to allow the texture to not only push outwards making the shell necessarily larger, but also inwards, such that the average radius stays approximately the same. The factor 15 then extents the maximum range for the displacement to that value. Texture : Use the Texture dialog to choose and customize the texture that controls the Texture Displacement modifier. See the page on the Texture key subsystem for information on how to setup a texture. Modifiers: Texture Displacement

The Bump Modifier is designed to add individual bumpy extrusions to a mesh. Position, orientation and detailed shape of the bump can be controlled. ​ To add a Bump Modifier to the Modifier Stack, click on the Add Modifier button (the + sign under the Modifier Stack) and select Bump. ​ The modifier appears at the end of the stack. It is important to note that the detailed effect of the modifier may depend on the position within the stack. Therefore experiment how it interacts with other modifiers before or after in the list. ​ Different properties of the Bump Modifier is controlled in different places. ​ The Control Panel under the Modifier Stack has several check marks: ​ Enable: Enable or disable the Bump Modifier ​ Symmetric: By default the bump will be cylindrically symmetric around its direction axis that can be seen when the Widget is on. Then the check mark is on. When the Symmetric flag is off, then the bump will be infinite in one direction and controllable in the other. ​ Radial: When the Radial flag is checked, then the bump will be applied radially from the coordinate center of the Widget. Otherwise it is parallel to the directional axis (pink) of the the Widget starting in the plane that contains its coordinate center. Widget: Posititon & Orientation The position and orientation are controlled with the Widget. The numerical control panel for the Widget can be opened by clicking on the Widget button in the Control Panel. Alternatively, use the interactive Widget controls on the left side of the 3-D views. As usual, during interactive control use the x, y and z keys to restrict moving and rotating actions to a particular axis. Magnitude: Shape & Size The shape and size of the bump are controlled from the Magnitude Graph that is accessed in the Control Panel under the Modifier Stack. ​ The Magnitude Graph works the same way as other graphs in Shape. For details see the user manual entry for Graphs . ​ The shape of the bump is set using an Analytic function or a Point graph, where the "x" is the distance from the local coordinate system (widget axis) is cylindrical coordinates. For the "symmetric", i.e. cylindrically symmetric case, the values at negative x are ignored. ​ By default the shape of the bump is set to a Gaussian function. ​ The overall size of the bump can additionally be controlled using the f0 parameter in the top left corner. Magnitude: Change the bump structure The detailed shape of the bump can be arbitrarily complex. This can be achieved by changing the Analytic function as shown in the examples on the right. Alternatively, for even more arbitrary complexity use the Point function by clicking on the Function drop-down list. Edit the Point function following the instructions in on the Graphs page . ​ Mesh resolution: Note that the application of the Bump Modifier may lead to poor mesh resolution in the bump. Currently the mesh resolution can not be improved locally. Therefore, if necessary, the overall mesh resolution can be increased by increasing the number of Segments in the Primitive tab of the object. Modifiers: Bump

Key Sub-System: Particles Many astronomical objects, especially nebulas have filaments with complex structures. Often these can not be reproduced easily as analytic or point functions of coordinates. Particles are a way to place emission in specific regions without the limitations of a functional description. The particles serve as small spherical regions where the overall gas distribution will be sampled for rendering. The advantages are, however, somewhat balanced by disadvantages related to the non-continuous nature of particles and the way they are placed in the model. Therefore careful evaluation should be applied to whether this is a suitable tool for your goal. ​ On the right is an example of spiral arms applied with the Draw tool on the surface of a flat disk. Below are the renderings with (right) and without smoothing (artificial "seeing") applied. General Workflow ​ Particles can be applied to a mesh by two methods: 1. using the "Draw" tool to place them at specific positions on a mesh using a 3-D cursor that slides over the surface mesh.2. randomly over a surface or filling the volume. The volume particle number density can be controlled by the Distribution function. ​ Once a first set of particles has been applied and the density the distribution of particles can be adjusted using the Draw or Erase tools. ​ The physical properties of the particles, such as density or temperature, can then be adjusted as a function of position using the usual modifiers. General Parameter Panel For the particles to render at all, in the General Parameter Panel of the object select "Particle" from the Input drop-down list . Particles tab ​ In the Particles tab you control the uniform but random distribution of particles in the mesh volume or along its surface. ​ Num: The number of particles to be distributed Size: The size of the marker circle in the 3-D views of the 3-D Module. ​ Displayed: The percentage of the total number of particles that is to be displayed in the 3-D views of the 3-D Module. If the number of particles to be rendered is very large, it may be convenient to display only a fraction of them in the 3-D views. Seed: The seed of the random distribution of particles. Change this number to change the distribution. Container: From this drop-down list you can select between Volume and Surface. For Volume the particles will be evenly distributed within the volume of the mesh. When you choose Surface, they are placed on the surface. Buttons: ​ At the bottom of the Particles tab is the button (left) that needs to be pressed to apply the particles or redistribute them according to the parameters of this panel. ​ ​ The second button is used to save the parameters in an ASCII file including all its attributes, including their position in Cartesian World Coordinates, their velocity, the density n and pressure p. ​ The third button open a dialog to load external data as particles. This allows one to visualize a variety of external data, including hydrodynamic simulations in order to extract spectral information such as position-velocity diagrams. Using this dialog a variety of ASCII data formats can be loaded. Draw particles: ​ In order to place particles in specific positions that can not be described with functions, Draw and Erase tools is provided. ​ You access the particle tools via the buttons in the Particles tab on the left side of the 3D Module as shown on the right. ​ When the Draw or Erase buttons are activated an orange 3D cursor in the form of a cylinder appears on the surface of the active mesh. You can move it around with the 2D cursor, it will stick to the surface and place particles on the near side of the mesh at a certain rate within the volume of the cylinder. Using Alt-left-drag places the particles on the far side . Draw tool parameters: ​ The parameters for the Draw tool can be adjusted in the Tools tab on the right side of the 3-D Module. This tab displays the parameters of the currently active tool. The Name parameters identifies the currently active tool. ​ Since the Draw tool is a cylinder , its geometric parameters are: Radius and Length in units of the spatial domain. The orientation of the 3D cursor is always with its axis perpendicular to the local surface mesh triangle. ​ Transparency: using the slider the transparency of the 3D cursor can be adjusted. ​ # Particles: The number of particles that will be placed at random positions in the volume of the 3D cursor per unit of mouse movement. The value should be 1 or above (not as shown in the image or the parameter panel on the right). If set to 1, a single click places 1 particle at a random position in the volume. To place individual particles at very specific positions, choose a small radius and length for the curser and click at the desired position. ​ Density: The density of the particles. This can be modulated or scaled as a function of position using density modifiers in the mesh object with the Scale or Add options, including textures. ​ Particle Size: This parameter is currently decripated. The radius of the rendered particle is now set in the Render Size parameter located in the Input parameters of the objects Input type (Particles). If you enable the Pixels flag, the Render Size is in terms of pixels in the Render Module. ​ Modify: When activated the 3D cursor does not generate new particles but modifies the properties of the particles that come into its volume to have the current properties set for the tool, mainly the density. ​ ​ ​ Erase tool: The Erase tool is activated with the corresponding button in the Particles tab to the left of the 3D views. It deletes particles inside its volume. It has only the parameters of Radius , Length and Transparency for the cylinder that makes up the tool. ​ The Input Parameters dialog that opens when you click on the Options icon after selecting Particles as Input in the General tab of a mesh object. ​

Shape The interactive 3-D astrophysical laboratory Images inspire us. Images lead to ideas. Shape was made as a tool to test astrophysical inspiration. Play True or False. By finding out whether an idea works or not, either way, we deliver new insight into nature for ourselves and others. That is why with Shape we make 3-D images of the universe...and more... ​ Shape responds to your scientific creativity for morpho-kinematic modeling or spectral radiation transfer calculations. Create schematic educational visualizations or even photo-realistic images of astronomical objects. ​ Our Introduction and Overview gives you more information about what you can do with Shape. ​ UPDATE REQUIRED (January 21, 2022) Due to a bug in some renders after camera rotation, an update is needed. Please go to the DOWNLOADS for a link to the patch and instructions. SBa Galaxy This 3-D volumetric galaxy model was created in ShapeX based on a detailed analysis of an actual galaxy image. The Orion Nebula This volumetric 3-D model of the Orion Nebula was created using pure polygon mesh and path objects with radiation transfer computation for the scattering and absorption by the dust from the central illuminating stars. Proto-planetary disk with jet. The dusty disk of this proto-planetary object has an enriched structure using noise-textures added to a relatively low-resolution hydrodynamic simulation from the Hydro Module. The disk and jet were then separated using filters and assigned different emission (jet) and dust scattering (disk) properties. Ring Nebula For the creation of this planetary nebula the application of image texture mapping along the line of sight allowed to include details of the dusty globules at precisely the right projected positions in the nebula. The environment of Eta Carinae This is the complex mesh structure that Mehner et al. (2016) used to model the fast expanding gaseous environment of the massive Eta Carinae stellar binary system. Eta Carinae Homunculus model This simple bipolar model of the dusty Homunculus around Eta Carinae demonstrates the multi-wavelength modeling capabilities with ShapeX. From left to right the wavelength range of the rendering moves from the optical to the infrared. About Shape was created by Wolfgang Steffen and Nico Koning. Shape is free software supported by the Institute of Astronomy, UNAM. Legal and Privacy Information User Guide Index Introduction Learn about the possibilities and limitations of astrophysical modeling and visualization in Shape. What types of physical models can be done. Whether you pursue research or outreach, find out what you can do and what you need to learn to successfully apply Shape in your field. Overview A quick tour is given through the integrated modules of Shape is given. We briefly describe how they work individually and how the general workflow brings everything together via interactive input but no need for a single line of coding from the user. Modules The modular design of Shape allows the user to concentrate on the job at hand. The desktop and the main toolbar are the hubs to get you around. In this section we describe the functionality of each of the modules, so you can quickly decide which one will be needed for your project. Goto Introduction Goto Overview Goto Modules Data Preparation Images, spatially resolved spectra and other data can be displayed as direct background references to build your models. Such data images need to be prepared carefully and correctly imported into Shape. In this section we describe how such data images can be prepared and set up in Shape. Goto Data Preparation Coordinate Systems Detailed knowledge of the various coordinate systems is necessary to correctly modeling in Shape. This is particularly true when kinematic are to be modeled. Here is a description of the coordinate systems in different contexts of the available tools. Goto Coordinate Systems Radiation Transfer Mathematical and physical details about the radiation transfer on the Cartesian grid in Shape are described. The physics and approximations for the calculations of scattering on dust particles are also layed out. Radiation Transfer

The Shell Modifier converts a normal mesh into a shell with user defined thickness. ​ The shell thickness can be set as a function of distance in the Magnitude dialog. Note that the shell can be generated outwards (positive) or inwards (negative) of the original mesh by changing the sign of the magnitude. Currently the magnitude can only be changed as a function of distance from the world coordinate center. This might change in future releases. The magnitude dialog allows you to define the thickness as an Analytic Function of distance or use a graph where you can generate an arbitrary function by manually placing points and setting the spline interpolation. The graph on the right shows the way it was done in this example. Note that only the newly generated mesh is affected by the shell modifier. ​ In the three pictures above the mesh is shown for three different settings. The first one on the left has both parts of the shell enabled. For the second one, the Outer geo flag was disabled. Therefore only the original object mesh remains. On the right, however, the Inner geo flag was disabled. Then the new shell mesh is left. Now the rendered volume fill out the whole space within the outer mesh of what was a shell. Note that the position in the Modifier Stack is important. If a Shell Modifier is placed at the end of the stack, the result will be a shell thickness that conforms to the Magnitude graph. However, if another geometry operator, such as a Bump Modifier or a Squish Modifier is placed below the Shell Modifier, then the final thickness may strongly different from that set up in the Shell Modifier. Caution: If the original mesh is locally complex and the thickness similar or larger than the local curvature, then the newly created mesh for the shell may self-overlap. This can lead to undesirable results. Make sure the thickness of the shell is compatible with the complexity of the mesh. Sometimes applying the shell in the opposite direction by inverting the magnitude of the thickness solves or reduces this potential problem. Modifiers: Shell

Overview ​ The mesh objects serve as containers of density and limit the volume where the density of an object is placed in space. The density modifier controls the density distribution within the volume fixed by the mesh container. ​ Several other modifiers work in exactly the same way as the density modifier and are therefore not treated separately. These include the temperature and the pressure modifiers . ​ In addition to the common parameters for naming and enabling modifiers, the density modifier has the following parameters: ​ f0: factor that scales the density that is otherwise controlled by the 3-D distribution defined in the Magnitude graph (see below). It is actually part of the Magnitude graph, but because of its frequency of use it is also exposed at this level of the panel. ​ Sigma: currently not in use ​ Operation : This is a drop-down list with the options: Replace, Add and Scale . These are the operations that will be used to determine how this density modifier affects a possibly existing sequence of density modifiers further up in the modifier stack. Replace mode: The first density modifier should be used in Replace mode . If there is a density modifier further down in the stack in Replace mode, then all previous density modifiers have no effect and only this one and those further down in the stack are used. ​ Add mode: the density of this modifier is added to whatever is the result of the previous density modifiers in the stack. ​ Scale mode: the density of this modifier is added to whatever is the result of the previous density modifiers in the stack. ​ In the example on the right there are three renderings of the same geometrical object with density modifiers as shown in the stack above the rendered images. The first image has a density with a point graph that changes as a function of the z-coordinate in cylindrical coordinates. See the graph below the rendered images and note that the Coordinates have been set to Cylindrical. This density modifier is label Ladder Strungs. It is located at the top of the modifier stack and is in Replace mode . ​ The second density modifier is labeled Global Decay and is in Scale mode retaining the default Spherical Coordinate system (see the second modifier graph under the rendered images). It scales the density that results from the first modifier with a normalized Gaussian as a function of distance. ​ In the final example, a Texture was included in the first density modifier. The texture scales this modifiers with the three-dimensional procedural texture of which a slice is shown below. How textures work in more detail is explained in the corresponding section of this manual on Textures. Modifiers: Density (Temperature, Pressure)

Modules In this section we give an overview of the functionality of the different modules and provide links to more detailed information on how to use them and their subsystems. Click on the Module Icon to the left of the description for more information and access to video tutorials on the module. 3-D Module ​ ​ In the 3-D Module the geometric and most other properties of a model are set up interactively. Description Render Module This module takes care of the rendering of image and position-velocity diagrams and a number of settings for other render options. Description Physics Module Radiation transport properties such as emissivity, absorption or scattering are set up as materials (species) in the Physics Module. Description Desktop Module ​ ​ The Desktop Module is your hub to all the other modules, project files, ShapeX configuration and more. Description Video Tutorial Math Module The Math Module allows you to set up variables and relations between them that can then be used throughout Shape as "global variables". Description Modifier Module The Modifier Module lists all modifier that are currently in use and allows you to change parameters of a selection of modifiers simultaneously. Description Maps Module The Maps Module displays channels maps of the 3-D model. The number and velocity range between the first and last channel can be set up. Description Animation Module Most parameters in Shape can be animated over time. This can be used to generate time variation of the models either for scientific modeling of time varying phenomena or for visualization purposes. Description Filter Module Filters for various physical quantities can be defined here. They can then be applied to objects in the 3-D Module. Description Movie Module In the Movie Module one or more animation sequences can be concatenated to a movie and exported for viewing with an external movie player. Description Export Module The Export Module exports the 3-D model into various output formats that can then be used as data for external use. Description Hydrodynamics Module Shape is the first astrophysical tool to introduce an interactive mesh-based setup for such simulations without the need of programming or scripting by the user. Description