Fixed hardware ray tracing issue

[pixelpunk-DE]

fixes xverse-engine/XV3DGS-UEPlugin #31

In the custom material function discard was changed to alpha = 0.0f.
Because discard does not seem to be supported in HW ray tracing.

[bell-one]

Hello pixelpunk,

I have issue with my unreal 5.2 with hardware raytracing
and I tried your commit with two binary files chang but it doesn't show any different with my project,

Is there anything for me to do more then changing M_GS_relight.uasset / M_GS_unlit.uasset in plugins?

[pixelpunk-DE]

Yes, that's all that changed.
On both materials it should change in this custom node:

from discard to alpha = 0.0f;

Which errors do you have in the shader of the original branch?

[Ben-Garcia-DB-Solutions]

Implimenting this fix also works for me. Although I found I have the edit

if (power > 0.0f)
  	discard;

to be

if (power > 0.0f)
   	return 0.0f;

to get rid of errors. I think this is the correct adjustment but I don't know HLSL at all so not committing it!

[pixelpunk-DE]

Yes. I am not an HLSL expert myself. But as far as I understand is that the discard operation is a rasterize operation, which is not supported in SM5+ raytracing.
So instead of discarding the pixel, we set it to be transparent. That adds a bit to the shader costs but makes it work with h/w rt.

So please feel free to add it :)

[LindenChance]

Thanks so much for finding this. I had to replace 2 discard statements to get mine working.