External cages for clean normal and AO baking?

Kot_Leopold

Hey guys,

Most of the time I don't get clean bakes out of xNormal because of how my low-poly doesn't encompass the high-poly. They overlap in a lot of areas and I think this is due to me using Topogun for all my retopo needs.

My question is, how do I go about building a cage after all the UV's are done? My primary modeling tool is Maya and I couldn't find a cage option in there. I know max has one.

xNormal has some options for building one like that cage bloating slider as well as the option to move individual vertices. But there's got to be a faster way.

I watched the xNormal overview over at Eat3D a few times already but I still don't quite grasp how to build a custom cage and what things to keep in mind when creating one.

If anyone could shed a light on this, I'd be grateful!

Bauken

Best way I've been able to find is through the Rendering toolset. Go to Lighting/Shading > Transfer Maps. This is also a way to bake normal maps in maya. add your model to the 'Target Mesh' category and under display, change it from Mesh to Envelope. this gives you a transparent red cage that you can inflate with the % slider and you can also tweak the verts to get a better bake. Select the envelope and then you can export it as you would a low poly model.

-Cheers

mazz423

If your using Maya it should be as simple as duplicating your low poly, moving your verts until it encompasses your high poly and exporting it as another obj along with your low poly. In the past I'd tried doing this in Maya and it would mess with my vertex order making it pretty much useless, however recently that problem seems to have magically disappeared. Maybe it's because Im now using Maya 2012, not sure.

You shouldn't need to use Mayas cage builder, which it does have burried away somewhere, can't remember where exactly. The above option has been tried and tested a few times though without problems.

Frump

Import your low poly and high poly. In the move tool settings there's an option to move along the normals: turn that on. Switch to vertex mode, select all the verts on your low poly and move out along whichever axis, probably Z, until it covers the high poly. Afterward you can tweak it as much as you need, then simply export the new mesh as obj and add it as external cage in XNormal.

That will get you a solid cage, and it's the same principal as the way Max creates a cage, you're just inflating the mesh along its normals.

What to keep in mind is just that there's not a ton of overlap in your cage and that it covers the whole high poly. I am not positive but I think in Xnormal the cage is only used for distance calculation, so as long as you have all of the high poly mesh inside of the cage you should be good.

Kot_Leopold

Frump wrote: »

Import your low poly and high poly. In the move tool settings there's an option to move along the normals: turn that on. Switch to vertex mode, select all the verts on your low poly and move out along whichever axis, probably Z, until it covers the high poly. Afterward you can tweak it as much as you need, then simply export the new mesh as obj and add it as external cage in XNormal.

That will get you a solid cage, and it's the same principal as the way Max creates a cage, you're just inflating the mesh along its normals.

What to keep in mind is just that there's not a ton of overlap in your cage and that it covers the whole high poly. I am not positive but I think in Xnormal the cage is only used for distance calculation, so as long as you have all of the high poly mesh inside of the cage you should be good.

Kyle, you're a life saver! This is exactly the type of answer I was looking for and the way you explained it all makes absolute sense. You just answered every question I had about creating an external cage for aid in baking cleaner maps. Simple and efficient, I'm going to stick to your method that's for sure!

And thanks to others for chiming in on here, I really appreciate it!