Baking Picatinny rails

ThePugLife

I've been trying to bake picatinny rails where the teeth of the low poly rails are separate elements from the main body, but cant seem to get a good result. I don't know if I' not setting the projection cage up right or what.
I've searched the forums to see if I could get an answer but didn't find anything so if anyone could guide me on the right path for the proper workflow, that would be greatly appreciated.

Current projection cage:

GlowingPotato

I didn't know projection cages could be composed by multiple meshes... Does this works ?

ThePugLife

They're the same object, just different elements

commador

What do your results look like on the low poly mesh?

Mark Dygert

GlowingPotato said:

I didn't know projection cages could be composed by multiple meshes... Does this works ?

Yes it can be multiple meshes but in this case, no it won't work. He is going to get seams.

GlowingPotato

Mark Dygert said:

GlowingPotato said:

I didn't know projection cages could be composed by multiple meshes... Does this works ?

Yes it can be multiple meshes but in this case, no it won't work. He is going to get seams.

And its fine if the pieces intersect each other ?

musashidan

GlowingPotato said:

Mark Dygert said:

GlowingPotato said:

I didn't know projection cages could be composed by multiple meshes... Does this works ?

Yes it can be multiple meshes but in this case, no it won't work. He is going to get seams.

And its fine if the pieces intersect each other ?

Why didn't you model this as a single piece of geo? The normal vectors of the separate meshes won't be continuous so seams will occur in the bake. Baking multiple objects/elements is no problem but it's usually for objects that are actually supposed to be separated. You can edit the normals to blend them together but it would be much quicker to just build the model again, or dynamesh it (or similar)

GlowingPotato

musashidan said:

GlowingPotato said:

Mark Dygert said:

GlowingPotato said:

I didn't know projection cages could be composed by multiple meshes... Does this works ?

Yes it can be multiple meshes but in this case, no it won't work. He is going to get seams.

And its fine if the pieces intersect each other ?

Why didn't you model this as a single piece of geo? The normal vectors of the separate meshes won't be continuous so seams will occur in the bake. Baking multiple objects/elements is no problem but it's usually for objects that are actually supposed to be separated. You can edit the normals to blend them together but it would be much quicker to just build the model again, or dynamesh it (or similar)

oohh its not me modeling that, i'm here just questioning his workflow. =]

EarthQuake

Yeah just model it as a single, watertight chunk of geometry. With modern hardware the extra triangles this will use is completely trivial.

ThePugLife

Thanks for the responses. The Highpoly is modeled as a single piece, I just wanted to save as many tries as possible and Ive seen people have the teeth of the rails as separate pieces on the low poly and gotten good results .

Dan Powell

Intersecting geometry typically isn't great for baking to - so definitely model this as one piece instead of splitting the teeth to save geometry; as above, the extra triangles is negligible (even on mobile devices).  =P


The fact that you're baking at all suggests that this doesn't need to be super low poly, because if it was for a mobile device it would probably be cheaper to just model the smoothing with chamfered geometry - then the devices's GPU wouldn't have to load and render the normal map at all?

Plus, by modelling it as one object you will save UV space (because there won't be any geometry hidden underneath the teeth), and achieve a greater texel density. 

The cage will also be a lot easier to make if it's one object

Thane-

Looks like Max your using. Keep in mind i think max will push the cage verts out differently after the first push, and not in their proper averaged normal directions like the first push. However that could have just been a bug i got while using Max 2014, no one ever confirmed it happening on their end.

musashidan

Sorry @GlowingPotato responding from my phone and didn't see you weren't the OP.