Sometimes I have problems with stencil shadows. In this model I just made, for instance:



The Mesh Tester in MED tells me there are NO open meshes (I merged some open-mesh vertices in MED). Still, the engine draws lines from the model to the shadows.

Most of the time, I have to try to find the unreliable geometry and rework it in my 3D app (Hash Animation Master). But It's becoming improductive: I would like some hints about what could cause these lines, other than the typical open meshes.

The model is here for download: LINK

Any help?

Emilio

The mesh is not closed - I see this from the shadow streaks. They lead to the open parts of the model. Your download link didn't work - do you have another one?

Hmm.. the download is there, i just downloaded it..

the link is: http://www.moscafilms.com.br/temp/michelle_MED.zip
http://www.moscafilms.com.br/temp/michelle_MED.zip


I know the obvious conclusion is that the mesh IS open. That's exactly the problem: MED tells me all the meshes are closed. Now and then I have this problem with shadows, and I have to rework the offending 'geometry' (the mesh that produces the shadow lines). Even if I end up with a geometry that is almost the same shape, the problem would be solved. For instance, I had some problems with eyeballs before, even when they were closed.

In the case of this model, I was not able to identify where the problem is.

you have 2 main problem areas, the belt and a separate part of the hair. you can simply see your mistakes by selecting the appropriate parts:



obviously, some face normals are upside down. if some faces are even separate, i cannot say, you'd have to convert toe file into 3ds and look it up in another editor, eg c4d offers the opportunity to correct these lil mistakes automatically.

Thanks for your tips, DaBroozar!

Well, it's not that normals are inverted: actually, this 'belt' is a double faced mesh: it was duplicated, flipped and weld together, like if it was a piece of cloth.

I had used this method before to create 'double sided geometry'. But it seems it means trouble. Do you think there's another way to create double sided triangles?


I also made another kind of belt - a solid one, not so thin.. but now and then I get the shadows problem. It seems that there are other 'rules' to apply to the model, besides 'open meshes'. For starters, internal patches also give me shadow problems.

Unfortunately I don't have 3D max or C4D. For now, it's just a trial and error process..


EDIT: Reviewing the manual... "Stencil buffer shadows can only be cast by nontransparent models consisting of closed meshes with no holes or intersections..."

Maybe these intersections are the problem (!) I'll work on this. THanks!