(fixed)[HOU-2916] Texture Baking

[andy_clarke]

Hi,

I'm doing some research into texture baking in VRay/Houdini and have come across a problem. Not sure if this is a bug or if there's a setting somewhere that I'm missing.

I have a fairly dense mesh which has been modelled at real-world scale - in this case about 30x30x30mm. Having set the Baking Mode to 'Maps Baking', when I hit the Execute Baking button, it renders everything black. However, when I insert a transform SOP before the Baker Tool node and scale the geometry up x100, all of the maps bake perfectly. When scaled at x10, it only renders where the geometry is more spread out - in the denser areas, it's just black. I've tested with a simple sphere at different scales and getting the same problem.

Is there a scale threshold somewhere in the tool that I'm missing? I've played around with the sampling and resolution but nothing seems to make a difference. Or maybe it's just not designed to work on small scale geo?

If this sounds like a bug, let me know and I'll post with some pictures in the Issues section.

Many thanks,
Andy


Houdini 19.0.455
V-Ray for Houdini hash:fe945ef from 09 Dec 2021 11:01
V-Ray Core 5.20.02 [58987b7e] from 2 Dec 2021

[Dubbie99]

Check your shadow bias on your lights.

[chakarov]

Hi andy_clarke , I've reproduced the problem and it is definitely a bug. Scaling the mesh may solve the problem, but only if you don't want to bake lighting,shadows,scene reflections . The problem does not appear in V-Ray for Maya, so it could be related to houdinis default units. I'll try to find a workaround for you and will report the issue in our system.

[andy_clarke]

Thanks chakarov.

I'm looking to bake the maps only, not the lighting, so I'll do some more tests with the scaling. I need to check if the material scale (bump amount, triplanar scale, etc) needs multiplying to match, which might make it unworkable as I have lots of complex materials to get through.

Let me know if you find a better workaround.

Many thanks,
Andy

[andy_clarke]

Hi again,

I've just tested the scaling solution (adding a transform SOP before the Baker Tool) and I'm getting good results for the triplanar maps and procedural noise which are scaling correctly due to the rest attribute. However, the bump amount doesn't scale with the rest. I'm assuming this will be the same with the radius values in the V-Ray Dirt texture I'm using in other shaders.

Does anyone know if there's a way of controlling these, and any other scale dependent parameters, with the rest attribute?

Many thanks,
Andy

[chakarov]

The issue is fixed in last nightly build of V-Ray.