BC3n(DXT5n), No Cuda, Highest quality, artifacts

[maks_kosten]

I want to compress DXT5n texture without cuda, but something goes wrong with output image.

Example:
Command: nvcompress.exe -bc3n -highest -nocuda D:\dxt5n.png D:\dxt5nHighestNoCuda.dds
Command: nvcompress.exe -bc3n -highest D:\dxt5n.png D:\dxt5nHighestCuda.dds

In the image above you can see extra red shape. This shape appears for BC3n only with Highest quality and only with No Cuda.

It is worth saying that the extra figure in the original image has a color close to white(0.976, 0.992, 0.992 RGB)

Source image:

[nbickford]

Thank you for the bug report @maks_kosten! I was able to reproduce this and can confirm – it looks like the virtually imperceptible teal line in the original image crossing the tip of the triangle is messing up our BC3n CPU compressor. I’ll look more into this – thanks again!