How to properly bake multiple sub-tools into one texture map?

Adrian Pieroni

School's started back up again. Our instructor threw us a choice for one of three meshes to roll with that we need to texture, so I picked the goblin, which is already UV'ed. I need to make a normal, spec, and diffuse, so i'll be bringing this low-poly mesh into Zbrush to sculpt and get my normal map first.

https://www.dropbox.com/s/tk53lvc3im0iala/Goblin.jpg

https://www.dropbox.com/s/laip4b3vka8gsji/Goblin_UV.jpg

As you can see highlighted, there will be several sub-tools. I have never baked down multiple sub-tools into one texture map before, so i'm a bit unclear on how to go about this from Zbrush. It needs to be one 2048 texture map. I've been using Xnormal in the past for normal, AO, and cavity maps. My guess is that applying my usual method to this assignment will force me to import each individual mesh from Maya into Zbrush as a sub-tool, starting with the Goblin himself (who is one mesh), and then after sculpting, individually bake out him and each sub-tool one by one back onto the low polys that have been provided. This will create multiple texture maps though obviously for each mesh that I will be forced to composite onto the one texture map (sounds messy) or else they will overlap each other.

Is there something i'm missing, or is this how I should be approaching this assignment?

Neox

there are two ways i can think of

exploding you model, means you have to move your overlapping lowpolies apart from each other and move the highpolies accordingly.

or exporting only the the parts that don't interset and bake batch by batch of non intersecting pieces

both ways can be certainly annoying, but for the latter one we just released a small toolkit helping you to bake all your individual parts in one run.

http://www.polycount.com/forum/showthread.php?t=125244

You could even set up every piece to render in it's own batch to avoid any overlapping. But usually it's fine to split it like, head/legs/arms in one batch, torso, boots and hands in another etc. No need to split it into hundred of batches.

I'd suggest baking with no padding whatsoever and generating the padding in Photoshop later.

EarthQuake

To make it easier you can also model with less separate chunks.

For instance, what is the reason the buckles on the shoes or on the arm are modeled as separate objects? If you merge those into the shoes and arm respectively that's 3 less mesh chunks you have to worry about explode baking or baking separately.

I really like to avoid baking separately as its a big pain if say, you need to do major adjustments to the uvs and have to rebake everything. Even with scripts/tools this will still be a pain.

Generally, if it doesn't need to come off, if it doesn't need to animate (like an ejection port on a gun) and it isn't going to give you problems when baking (like complex overhangs) merge it into the base mesh. You'll make baking easier, uving easier, texturing easier, and you'll even save some texture space.

Fingus

If you're planning on baking in zBrush the MultiMapExporter plugin gives you the option to merge all maps into one file. Still, zBrush's baking can be a bit janky so I'd recommend just decimating and baking in xNormal.

Adrian Pieroni

Thanks for the replies guys. Fingus, your suggestion is definitely the quickest and would be a huge time saver, considering everything i'm bringing into Zbrush and sculpting from is already UV'ed. I've compared the bake quality between Xnormal and Zbrush though, and Xnormal seems to bake with better definition.

Still, it's nice that multi-map exporter can composite all of the sub-tools into one map...