Bug in handling bitmap alpha channel

V-Ray V-Ray GPU Issues
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1

Hi,

i just found a bug in Vray GPU Next. I’m using a tga file with alpha channel as input for a blend material map. To use the alpha channel as my map i switch the “RGB Channel Output” to “Alpha as Gray” in my texture. This procedure works fine with Vray Next but Vray GPU Next does not handle this correct. To get the same behaviour in Vray GPU Next i have to use a simple black/white map as a texture in my map slot.

Hope you understand what i mean. Here are some screenshots of my setup.

Best regards,
Ralf

VrayNext.PNG.jpg
VrayNext.PNG.jpg1893×1038 366 KB

VrayGPUNext.PNG
VrayGPUNext.PNG1894×1020 395 KB

AlphaAsGray.PNG
AlphaAsGray.PNG339×621 19.4 KB

2

Hey Ralf,

Can you send me the scene?

3

Hi Peter,

i just send you an email with my scene.

Best regards,
Ralf

4

Any news about that?
On V-Ray 5 GPU there ist still such a problem.
On V-Ray GPU “Mono output” switch of VrayBitmap is ignored. On CPU is ok.

GPU alphajpg.jpg
GPU alphajpg.jpg960×922 161 KB
CPU alpha.jpg
CPU alpha.jpg979×928 194 KB

5

Your case is different from the above. It’s an export problem with Mix map explicitly. Logged as VMAX-11455, it will be fixed for the next release.

6

I think there is a problem with V-Ray GPU and its handling of “Mono output” switch.
For instance this setup doesn’t work on GPU (preview in Slate is OK but render is wrong)

alpha.jpg
alpha.jpg897×509 83.9 KB
:

7

This will be fixed for the next release too.