Intersecting Meshes and Baking, need help

HashBrownHamish

Hey i have a quick question i'm making a greek column and i was going to bake in the textures since i want to make it game ready but something is troubling me.

This is very much a noob question so pardon my incompentence in advance.

When i make my model does it need to have all the faces connected or can i leave them "Floating" on each other? This might be troubling for baking because i heard i can't have faces intersecting.
Here are a couple of photos to make my question clearer:

Top Half of model and main cylindre attached:




Top Half of model and main cylindre detached with both of them intersecting:

Bruno Afonseca

If by baking you mean baking a normal map, then intersecting is not a problem. When baking this, you need to 'explode' the mesh, that is, moving elements away from each other. Do that with an 'edit poly' modifier on the top of the stack so you can easily return to the original state afterwards.

The only problem with this kind of intersection is that you lose the texture space on the flat face covered by the cylinder.

If you mean baking lightmaps, then yeah, might be a good idea to have the mesh welded so you don't get light bleeding.

But anyhow, try both and see what happens, that's the best way to learn

throttlekitty

Intersecting meshes are fine, you can easily save on tris this way, espeically in small nooks like that. Baking this way works just as well. In your example with the circle meeting the square, there will be a lip of normals, and a huge black spot inside in the AO. There are cases where you may need to do some cleanup in Photoshop due to pixel bleed, but generally it's fine.

One thing that you need to be aware of is how the low poly will be lit, since in-game this starts at the vertex level. So if you had a large square with a medium cylinder sitting slightly inside, and the model is falling halfway in light/shadow you will see more light across the square face where you realistically shouldn't.

HashBrownHamish

Thanks for the advice

I "exploded" the mesh and made sure the cage wasn't intersecting any meshes to be sure and i will probably use this is in the future as well