bump map + normal_smoothing?

suvakas · Post by **suvakas** » Thu Jun 05, 2008 11:02 pm

Hey,
I can't get the bump maping to work with normal smoothing.
Here are two images, 1st has a teapot with a bump map applied and 2nd without it.

Zom-B · Post by **Zom-B** » Thu Jun 05, 2008 11:47 pm

Seems to be related to this

Sould the connected to Sun Lightsource...
simply subdivide your mesh until your RAM bursts and you'll get nice shadows

Post by **OnoSendai** » Thu Jun 05, 2008 11:50 pm

hmm, can you do a test with a very small meshlight in the same position as the sun, instead of the sun+sky?

supraserv · Post by **supraserv** » Fri Jun 06, 2008 12:12 am

I had the same problem months ago when I was creating my Egyptian scene. I noticed the same in some Maxwell renders elsewhere. I made a thousand tests but they didn't help.

suvakas · Post by **suvakas** » Fri Jun 06, 2008 12:53 am

OnoSendai wrote:hmm, can you do a test with a very small meshlight in the same position as the sun, instead of the sun+sky?

Still same...

cookieofdoom · Post by **cookieofdoom** » Fri Jun 06, 2008 2:51 am

I'm pretty sure that kettle would never work right anyway.

suvakas · Post by **suvakas** » Fri Jun 13, 2008 9:44 am

Hey Ono,
What do you think is the cause of this issue?
The problem is still there in 1.1.5 too...

v_mulligan · Post by **v_mulligan** » Wed Jul 30, 2008 5:08 pm

Hmm... I've seen something similar on Renderman-compliant REYES renderers. If you write a shader that calculates the bumped normal by perturbing true geometric normal rather than the smoothed normal, it looks a bit like that. I don't know why it only seems to be affecting direct light, though, and not reflected light. Of course, Indigo's a bit of a black box to me. Only OnoSendai can really say what's going on here.

v_mulligan · Post by **v_mulligan** » Wed Jul 30, 2008 5:13 pm

Hmm... Looking at it again, it looks like each of those polygons is either fully illuminated or fully in shadow, with regards to the emitter, but has proper intermediate levels of shading with regards to reflected light. Is there any chance that something that ought to be a float or a double is coming out as an int or a bool? Total stab in the dark, here.

Deus · Post by **Deus** » Wed Jul 30, 2008 9:53 pm

You are right mulligan it looks like the albedo direct lighting is completely broken

Ono maybe you should try general diffuse

color = cos( normal dot lightdir )

v_mulligan · Post by **v_mulligan** » Thu Jul 31, 2008 6:49 am

Don't you just mean normal.lightdir? The dot product of two vectors is equal to the product of their lengths and the cosine of the angle between them.

BbB · Post by **BbB** » Thu Jul 31, 2008 8:10 am

That always happens with sun light and bump maps on low-geometry meshes. No way around it but to increase the polys. Pretty much all renderers are affected by the way. Not an Indigo singularity.

v_mulligan · Post by **v_mulligan** » Thu Jul 31, 2008 8:19 am

BbB wrote:That always happens with sun light and bump maps on low-geometry meshes. No way around it but to increase the polys. Pretty much all renderers are affected by the way. Not an Indigo singularity.

Um... no. REYES renderers certainly don't give that sort of image artefact unless you've done something wrong.

Raytracers might with very bright light since some edge polygons will be shadowed by other edge polygons. That still doesn't explain why the direct illumination seems to be uniform across the lit half of the surface, though.

suvakas · Post by **suvakas** » Thu Jul 31, 2008 8:20 am

@BbB
Do you mean other unbiased renderers? Cause I haven't seen this kind of artifact with any other 3ds Max renderers i use.

zsouthboy · Post by **zsouthboy** » Thu Jul 31, 2008 9:04 am

Yeah not only that, I don't think this used to happen with Indigo, as well, but we never really had closure on it..

bump map + normal_smoothing?

bump map + normal_smoothing?

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