Baking Color And Occlusion Problem

[lisux]

Hi everybody.

Iam trying to bake the ambient occlusion and color from a model.

I have followed the steps in the odwiki by Jason Iversen but I a mstill getting a strange error.

I get a strangle, triangle like, pattern whe rendering using the -u option.

The model is perfectly rendered but when I try to bake something I get this strange patterns:

Somebody have sufferend similar problems?

I think that it is a geometry problem because I have used this option succesfully previously, but I can't guess what is the problem, even more, because in a regular mantra render (without -u) I get correct results.

Thanks.

[Jason]

Are you using displacement mapping at all? Mantra 8.1 cannot unwrap displaced surfaces, I believe. If you are, you have to try to emulate the displacement in the surface shader using bump mapping or whatever in order to get it working.

It looks like there is a grid pattern - the bucket edges are clearly visible. Try to render it with the -r option to force raytracing perhaps?

[lisux]

Are you using displacement mapping at all? Mantra 8.1 cannot unwrap displaced surfaces, I believe. If you are, you have to try to emulate the displacement in the surface shader using bump mapping or whatever in order to get it working.

It looks like there is a grid pattern - the bucket edges are clearly visible. Try to render it with the -r option to force raytracing perhaps?

Thanks Jason

I am not using displacements.

I have tried the -r option, much better but slower than using micropolygons. But there is an important limiatatiom: the -r option is not compatible with the -u option, then is impossible to bake using only raytracing. I am using H 8.1.704 Linux.

I have guess that many of the problems are in the interpenetrating areas where, several planes intersetcs, here the micropolygins pattern is more noticiable.

Another option to improve the results is to increase the shading quality, but to expensive.

This is the best I have get using an occlusion surface shader with bump mappint and a shading quality of 5:

Still having errors and patterns.

I think that Mantra bake option needs a lot of improvement. Hope for H9.

Finally I have to return to LightWave to generate the occlusion pass

[crunch]

Hi everybody.

Iam trying to bake the ambient occlusion and color from a model.

I have followed the steps in the odwiki by Jason Iversen but I a mstill getting a strange error.

I get a strangle, triangle like, pattern whe rendering using the -u option.

Thanks.

Just on the off chance, are there any overlapping polygons in UV

space? Things from the front & back faces of the model? This might

cause problems like that.

[MADjestic]

I think that Mantra bake option needs a lot of improvement. Hope for H9.

Finally I have to return to LightWave to generate the occlusion pass

Are you totally sure that this problem is not caused by the scene\geometry set up? Did you try reproducing this problem with a different set-up\geometry? Did you try posting the file with the problem? This problem can likely be caused by the user. Anyway, it would be interesting to find out what brings about this issue.

nnn

[doc]

I have to go with crunch on this one. The last time I saw these types of artifacts was

when I had overlapping primitives in uv space.

Luca

[lisux]

Thanks everybody for your replies.

Well after diving into te UVs of the model I have found some overlaping primitives, and then I suppose this is the source of the problem.

I have tried to make the occlusion bake with LightWave and at the first try I have get much better results than mantra:

Not perfect but better, now I am using this bake with mantra.