Modifiers: Image Texture

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.

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