Baking hi poly to low poly

Jacecr

I'm not really sure how to do this.Are there any good tutorials on the matter?I'm using 3ds max.Does the Hi poly have to overlap the low poly and then I select the low poly and press 0.Or does the low poly have to over lap the high poly?Please help.I've been trying to learn this technique for a few months now.

Spicypixel

Struggling with 3dsmax is one option, xnormal works a treat so I'd suggest looking into this - specially since the tool remains useful regardless of you learning maya later for some reason.

roosterMAP

this is the tut i leaned from: http://cg.tutsplus.com/tutorials/autodesk-3ds-max/how-to-bake-a-flawless-normal-map-in-3ds-max/

Jacecr

I'll check out the tutorials asap.the main thing i didn't understand is "Does the Hi poly have to overlap the low poly and then I select the low poly and press 0.Or does the low poly have to over lap the high poly?" I went to two tutorials and they both said something different.

Memnoch

The low poly must "cage" the high poly. This essentially means that you should use only as much low poly geometry as needed to cover the silhouette of the high poly form.

Think of it as taking the complex form you have with the high poly and break it down into simple shapes. If there is high poly geometry poking outside of your low poly then you need a bit more to encompass the shape. The best advice I can give to someone new at this is to, at first, fully understand how normal maps work before doing anything at all.

This is some of the best information all in one place-
http://wiki.polycount.com/NormalMap?action=show&redirect=Normal+Map

Highly recommend reading and re-reading that wiki page.

Piflik

Not sure what you mean by 'overlapping'...do you want to know if the lowpoly should be inside the high or the other way around? The lowpoly should be as close as possible to the highpoly, but they will intersect in places..at least that's how I do it (RTT in Max with MRay)...that being said, normal maps work best with concave details, since normal maps don't change the silhouette of the model and this is not so apparent with concave details...

Jacecr

Piflik wrote: »

.do you want to know if the lowpoly should be inside the high or the other way around? .

That's exactly what I'm confused about,so you you say they should intersect?

Snowfly

Yes, intersecting is ideal. Think of the low poly as an average of the high poly surface- you're setting each poly up to capture the highest and lowest points of the surface it covers more or less equally.

I_R_Hopo

Intersecting is best, but I've found that if you absolutely have to have one overlapping the other, have the high poly encase the low. You'll get big black areas where the low hasn't captured anything if you do your lowpoly bigger than your high.

Racer445

roosterMAP wrote: »

this is the tut i leaned from: http://cg.tutsplus.com/tutorials/autodesk-3ds-max/how-to-bake-a-flawless-normal-map-in-3ds-max/

don't use that tutorial, it contains lots of incorrect information. there's a page on the polycount wiki dedicated to pointing out all the errors in it.

PredatorGSR

It doesn't matter which is inside which really, they just should be as close as possible to each other. The polycount wiki has the most comprehensive info on normal map baking, I would refer to that for most questions that come up.

Jacecr

Ok! thanks so much.
I already watched the above mentioned tutorial.
http://cg.tutsplus.com/tutorials/aut...ap-in-3ds-max/
and it's a bit confusing with a beginner rating.:S

I found that exporting an object to zbrush or mudbox , producing a hipoly through subdivisions is easiest.The low sub and hi sub versions created in mudbox or zbrush are easily exported in .obj format.When loaded into max they're perfectly aligned and the rendered maps are more accurate.
Before, I was modeling the high poly then modeling the low poly in max.The normals that were produced were off.I think it was because my hi poly and low poly were not close enough to one another.
Thanks again!Wish I had a teacher again.Tutorials can really leave you asking more questions.