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Issues with xNormal baking & UVs

Hey there 3d masters!

First of all: That's really a nice place to find information. Read already plenty of threads here and abroad to fix my problems and while I did find lots of useful information that could help me out a lil, I just fail to nail it.

Okay, here's what I got:
[LIST=!]
[*]A mainly symmetrically sculpted highpoly with some polypaint and no subdivisions, no UVs. Fully done in ZBrush.
Highpoly
0LNVokes.jpg


[*]A lowpoly done in 3dsMax with UVs from ZBrush UV master (based on polygroups).
Lowpoly w/ polygroups:
bmZfzTss.jpg
UVs:
86XeLXHs.jpg B1fdTPgs.jpg [/LIST]
Obviously I want to grab all my maps from the highpoly and bake them on my lowpoly. First I tried projecting in ZBrush, but it was incredibly frustrating and didn't work so well.

So I wanted to use xNormal, unwrapped my 3dsMax lowpoly for it in ZBrush basing on their polygroups. I get results from baking, but only crappy ones. I highly suspect that my xNormal settings and/or the suboptimal UVs are to blame for that.

Examples
That's the ugly unusable result when I bake my Highpoly with polypaint on it:
j8Zzj87s.jpg 8W26UY2s.jpg

When I bake a highpoly without polypaint, I get this normal:
WrmClcXs.jpg
That looks quickly rendered in Max like this:
Nf1IPm6s.jpg

I baked the normal only with AA x2. It has those weird "negative reflections" in Max, I don't know what's causing that. Sadly that's the best I got yet!

How can I bake my polypaint as color map and sculpt as normal to my lowpoly with its UV? What am I doing wrong and how can I fix it?

I'm already a lil desperate about this. Been working for a whole week on this and it's an important assignment for uni I ultimately gotta finish until the end of the week. :S

Help much appreciated!

Replies

  • TheWildHunt
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    Has your green channel been flipped? Smoothing groups set? Maybe your unwrap doesnt have enough cuts to support such rounded geometry? I would export the high poly to 3ds as well, ive had my low poly shrunk to .1 scale on export a few times, sometimes it just moves. Also, try a lower edge padding, it looks like yoube got alot of intersecting parts after map dilation.
  • Tilanus
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    My max crashes when I try to load the highpoly itself, cause it can't handle so much polys. I can only get a decimated version of it into Max, which I used to build lowpoly upon. Checkermap looks fine now, but the baked normal still looks awkwardly distorted. Gotta try the edge padding!

    It's also flipped and has smoothing groups. I made a new retopo of the tongue and creature itself (with more verts now) and unwrapped everything manually in 3dsMax now. It really should work now.. :S

    Edit: I uploaded a new album, tried several xNormal configs for baking. I always flipped the green channel, baked with x2 Anti-Aliasing, never changed the standard settings for the highpoly mesh and decreased the edge padding to 8.

    SGCz1rab.jpg
    http://imgur.com/a/fNdux#0

    As you can see there, I made several test bakes with .obj and .sbm lowpoly meshes. Maybe someone sees the mistake(s). SBM offers the best results, the normal's still acting weird though and I can't figure how I get these black-white shines at Max Renderings?
  • Tilanus
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    Heya there, I just wanted to say how I solved things up:

    Baking setup: One gets clearly better results when baking subtool by subtool as opposed to complete lowpoly vs. complete highpoly. In order to do that, you gotta split up both meshes, lowpoly and highpoly. Takes more time, but the result is definitely worth the effort.

    xNormal: I experienced that the xNormal raytracing tool & external cages proofed really useful, xNormal cages rather useless. Indeed, you may get other results depending on your stuff. Also, if you can, use the native SBM xNormal format for at least the lowpolys and their cages. OBJ doesn't suck, but with SBM the results are cleaner and smoother.

    Aligning Low & High: I got the best align for lowpoly & highpoly when both meshes intersect each other, none should really incorporate the other fully.

    3dCoat: Didn't like it in the beginning (weird camera movement), but it really has an edge over other tools at retopo and UVs. Even if you're short on time, the trial is definitely worth it!

    Export/Import: The numerous mesh transfers between the tools may result in weird compatibility issues. You might take that into account when things not working the way they should.
    For example, my normal map was weirdly shaded because of 3dsMax's Gamma/LUT configurations. Disabling them solved it, the shading and smooth display of seams is alright now. :D - So, whenever you port from one tool to the other, I can only recommend: Check for your smoothing groups, UVs, shaders, render setup and other elementary configs. Don't - trust - dem monsters!

    ZBrush Projection: Trying to reproject all your highpoly details in ZBrush ('ProjectAll') on a lowpoly that was created at a later point in time is no good. Don't waste your time with that unless you're a crack on building flawlessly compatible topology. ;)

    High-Low workflow: That all said, if you ever intend to get a lowpoly from a highpoly in ZBrush, don't start as stupid as I had to in classes; just follow the tuts out there: Do the lowpoly first, do subdivisions and keep 'em, do all the fancy stuff, etc. etc. - Do NOT use DynaMesh in this workflow, since it simply destroys the downward compatibility to the lowpoly.

    Most of these things will probably be pretty self-evident to the more experienced artists here. I'm just leaving these here bundled, cause I didn't really find these essential rules as quickly in one painful week of endless research and trial & error. :poly114b: So, hope that helps anybody out there!

    ychLXAJ.jpg
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