Rendering two parts/materials/objects with distinctive colormaps

[ShawnZhang]

A customer requested the following,

"I have a data set that I have segmented into two regions (maybe three, the default “exterior” plus two defined by me). I would like to use VoltexHighQuality to render this. But what I would like is to be able to set one region (say label A) to one colormap/alpha value and have label B use a different colormap/alpha value. The densities of the two label regions are similar, so I cannot separate them based on the colormap density values alone. How do I do this? Any suggestions?"

The attached script should do the trick. Save the hx file under $AVIZO/data/tutorials, and load it.

The basic idea is using arithmetic module to mask out the part/material that is of interest.

Screen shot follow. In my case, I have 8 different labels, and I am extracting out label ID 6 and ID 7.

A few additional notes about improving volume rendering comparison.

1. When choose colormap, please make sure that you choose the colormap with transparency (alpha value) defined, such as the ones with "volren" string in the names.

2. SelectROI is a good idea to reduce the data being finally rendered on the screen, however, it does not reduce the total amount of data that you sent to GPU. You need to use the crop editor (available through the data module's property top-right icon list) to crop the data.

3. Then you can increase the number of slices to enhance the rendering quality.

Feedback welcome. Enjoy.

-Shawn

[shuom]

In the attached image, the (B==7) refers to the label set in B which is also indexed as 7, correct?

[forum_admin]

Correct. Label set with index 7 in B is used as a mask to pick out the voxels from the original image data.

Best,
-Shawn