I’d like to have a follow up chat about segmentation rendering. I found the vtk shader bug we discussed before so now shading can be made to work (no PR yet, but it’s a small set of changes). [image]

[image] pieper: This one was done by generating the RGBA volume and then rendering withe the GPU ray cast (once the shading was fixed). I’ve tried to colorize volume rendering using TotalSegmentator’s segments (see implementation ), but the result looks quite bad: [image] The main issue is …

The fix is in this post. No, I don’t think it was ever merged. [image] Color Volume Rendering: vtkDataArray Indexing Web Hi @Alireza and @sankhesh - Regarding RGBA rendering, Sankesh and I discussed some issues I was running…

Thank you, this is very useful. Is component 0 correspond to the alpha channel in the shader code? (in CPU memory the component order is RGBA) With the shader code change, the results look different, a bit better, but I had to dilate the segments and there is still problem with if I don’t boost the…

[image] lassoan: Is component 0 correspond to the alpha channel in the shader code? (in CPU memory the component order is RGBA) I’d have to go back and look - I remember the logic was odd. [image] lassoan: boost the opacity of segments that have low intensity Yes, that’s what I meant …

I’ve updated the gist and uploaded the test scene here . I experimented with applying Margin effect - expanding all segments expand by 3mm (not quite Voronoi but should be OK for a quick test) - but it did not make a big difference. With or without margin growing, there are still those dark artifacts…

I still think this is better than both the surface rendering of segmentation (lower left), and its labelmap (lower right). But the background and intestines are too close and removing the background seems to remove the intestines as well. For me the real benefit of RGBA is to replace the slow 3D mo…

Here it is with the background masked out (same ordering): [image]

I think what we miss for a good-quality volume rendering is smooth surface normal vectors. Surface normals may come from the original image, but it we only get surface normals in regions that have much higher intensity compared to surroundings, which are typically only bones and contrast material fi…

My take on this :wink: [image] This kind of hybrid display may help speed up the review of individual cases.

The Shift slider in Volume rendering is too sensitive, and it would be great if it would be a ctkRangeWidget to enable entering range numbers … [image]

Volume rendering colorized with segmentation

Development

rbumm (Rudolf Bumm) December 12, 2022, 1:11pm 21

Hurrah.

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Volume rendering colorized with segmentation

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