ZBrushCentral

Baking Zbrush highpoly models into LP models

ZBrush Usage Questions
#1

Hello, ZBCentral residents ))
Hope you can help me with a problem I’ve been having.
Say, I have a highly detailed ZB model with dozens of subtools, edited with clip brushes, maybe extracted meshes etc… Now, how would i go about transforming all that chaos into a relatevly LP model? The obvious option is to merge subtools, retopo and that’s it. But here the isssue of UV coordinates comes into play. How do I bake all those high detailed sculpts, if HP mesh doesn’t have a UV map (since it consists of dozens of merged subtools)?

Sorry for a slightly tangled explanation, btw )) Hope the collective wisdom of ZB Central will aid me )

#2

I asked this same question of a professional game designer, and he told me it may not be possible to go backwards from the high poly model, if you did not originally design your model as a VERY low poly in some other program like 3DsMax or Maya. He personally preferred Max.

I was shocked at how few polys the game figures actually had, with sophisticated bump maps to make them look “real”, but they were actually very flat surfaces, even the Viking Maiden in full battle armour was just 500 polygons or so. I’m trying to do horses, and can’t get them below 2,000 polygons without losing their true shapes, but then, I’m trying to do it backwards in Zbrush, so will probably need to purchase 3DsMax…

~Traveler in Thyme, running backwards

#3

It is entirely possible to go from high poly to a low poly mesh, even if you don’t start with a basemesh with predetermined edge flows and etc. This is typically my workflow, build the high poly either in 3ds max or starting from something like zspheres. Then bring the high poly into 3ds max (if starting in zbrush) using decimation master to lower the poly count of the high poly enough for max to support it or retopologize. Next build the low poly in max over the high poly mesh while trying to match the silhouette as closely as possible with as few triangles as possible. Once that is done I layout uvs on the low poly and project my normals, occlusion, and etc from the high poly onto the low poly.

Only your low poly needs uvs, unless you’ve done some poly painting/created texture maps and you want it transferred to your low poly uv’s. In that case you can simply use zbrush’s auto uv tools on your high poly. Make sure you have those maps applied to your high poly in your modelling application and when you project/bake the details onto the low poly it will transfer those maps over to your low poly uvs.

The workflow should work in just about any modelling application. You can even use xnormal to do the baking if you want, but you will still need a modelling application to build the low poly mesh/layout uvs.

This video shows a fairly good example of the projection/baking process in max: http://cg.tutsplus.com/tutorials/autodesk-3d-studio-max/next-gen-weapon-creation-day-3-unwrapping-and-texture-baking/ . The object is created entirely in max but the process for projecting is essentially the same as if you started in zbrush as long as you can bring your high poly into max.

#4

Thanks for informative and detailed explanation, Nstine, that helped a lot )) :+1:
I had some vaguely similar ideas in mind, but your clear layout of the issue helped me structure those obscure “thoughts on the matter” into an understanding of the process ))
sigh Guess some shortcut for the lazy, a magic trick, which I knew nothing about, was too much to hope for anyway :roll_eyes: