Slightly confused: Baking normal maps onto a low-poly object!

Stirls

At the moment I have a high-poly model. I'm beginning retopology for a low-poly version, but I've never baked normal maps before. The model doesn't have any UV's as of yet.

So I'm feeling lost. Did I screw up completely by not UV mapping first? If it's any help I'm using zBrush.

How do you folks create normal maps for a high-to-lowpoly workflow?

Bek

http://wiki.polycount.com/NormalMap

Normal maps are complicated at first, took me a long while (and a lot of excellent posts on polycount) before I really understood them, so don't worry if it seems like a lot to think about.

Yes you need UV's. Think about what UV's are (2d mapping of your 3d object) and what normal maps are (2d images).

Stirls

Bek wrote: »

Yes you need UV's. Think about what UV's are (2d mapping of your 3d object) and what normal maps are (2d images).

Yes, I'm aware that I need UV's. What I meant to ask, however, was whether I needed to UV map the high-poly or the low-poly before normal mapping.

Thank you for the response, I'll check out that link.

.Wiki

You need the uvs but you need them only on your lowpoly mesh. If your highpoly mesh is just for the baking process leave it as it is.

Stirls

Alrighty! Thanks.

[Deleted User]

What Wiki said --a lot of people for gaming go crazy on the hi-res without worrying about the hi-res uvs since it's only to be used for baking. But I was also advised that UVing your Hi-Res may come in handy as well--it can help you put some details on it especially for complex shapes with less distortion (e.g. you can apply a honeycomb pattern texture on your hi res character's suit, then use it to deform).

Stirls

Paololazatin - If I was to UV my high-res, what happens when I retopologize? The whole layout of the model gets redone. I'll investigate into it more, but I was thinking of UVing my model at its highes resolution first just in case. Thank you!

DanArt

Well explained.

LRoy

paololazatin wrote: »

What Wiki said --a lot of people for gaming go crazy on the hi-res without worrying about the hi-res uvs since it's only to be used for baking. But I was also advised that UVing your Hi-Res may come in handy as well--it can help you put some details on it especially for complex shapes with less distortion (e.g. you can apply a honeycomb pattern texture on your hi res character's suit, then use it to deform).

This is not really necessary. You can use things like zbrush's UVmaster to do UV's if you're applying a tile or something and don't need to worry about the layout.

The workflow is typically highpoly - lowpoly - UV - bake highpoly onto the lowpoly - texture

cryrid

If you're UVing the high res for the purpose of creating polygroups or applying a sculpted pattern, you can pretty much treat them as a temporary set. Once the groups are created and the patterns applied to the actual geometry then they no longer have any real use except in a few scenarios. It's generally easy enough to apply the type of layouts required for these things to a sculpt in zbrush, and you can apply them at any point in the process whenever you feel the need. It's not uncommon to go through several sets for a single model.