Maya 2009 Transfer Map Normal Map Baking (digitizing)

Brian "Panda" Choi

So I'm attempting to bake normal maps (and eventually AO maps) through just Maya's Transfer Map tools

I bake, and I get essentially very "digitized/bits" for normal maps, instead of something that looks smooth . . .

I've been hacking away at this for a straight 6 hours, does anyone have any idea what is wrong and what to do?



The green mesh = high res
Grey Mesh = low res
Red Mesh = the transfer map envelope

m4dcow

Your low res has hardened normals, smooth them and try again.

Brian "Panda" Choi

yes, heisenberg!

#hadtosayit

Brian "Panda" Choi

I'm getting similar issues with other parts of the model when I try to bake the normal map. Essentially, I get maps with, once again, digitized markings all over and crazy things happening.

Oh and smoothing out the normals (averaged them) for the wire tree somewhat worked, but I'm not getting the deep cuts that should be conforming to the high res.

m4dcow

Go to your bump2d node in your material and change the "use as" attribute to be "tangent space normals". That should solve the pixelated issue.

Brian "Panda" Choi

so m4dcow, this is the first time I've had to smooth normals (I'm assuming that's the Averaging Normals, right?) due to "I can't make anything work until I do this."

So what technical purpose does doing this serve in relation to a (I'm assuming) low-poly model (or high res mesh for that matter)?


What does it specifically do and why would I need to use it?

throttlekitty

I'd suggest using Smooth/Harden Edge/Set Normal Angle over Average Normals if these are being sent out to a game engine. It's easier to manage and make corrections to the smoothing afterwards.

http://wiki.polycount.com/NormalMap?action=show&redirect=Normal+Map#Smoothing_Groups_.26_Hard_Edges
For the most part, smoothing on the low poly should more or less look like the high poly. As you saw, the faceted look fights with the normal map and doesn't look as nice.

In your radio model, you have overlapping UV shells, generally bad for baking normals. The overly pink and yellow bits should read as blue. This can be corrected by moving the mirrored shells one unit away, so they're not stacked and breaking the bake results.

m4dcow

Check out the wiki on Normal Maps
http://wiki.polycount.com/NormalMap#Smoothing_Groups_.26_Hard_Edges
For you issue, look at the "Smoothing Groups & Hard Edges"

Also look at this thread:
http://www.polycount.com/forum/showthread.php?t=73593

It is a similar issue to what you will have by having hard edges on your low, but a continuous uv shell.

Brian "Panda" Choi

What about this issue? Using the Transfer Maps tool once again, I'm getting these strange baking issues with the normal maps again.

The envelope is completely surrounding the high res model, and both meshes are more or less right on top of each other (in each other, etc.)

throttlekitty

Same issues. Hard edges give the faceting, and overlapped UV shells are the extra pink/green. -basically it's baking those areas twice and adding the results together. To fix this, move the overlapping shells one unit away (outside of the 0,1 space); they will be in the same spot mathwise, but not included in bakes like this.