How low can I go on my polycount without losing details when baking?

Kyle_butler

Hi, guys! I've had problems with this before, and I'm not quite sure if what I'm doing is correct.

Many models I work on, end up with washed up textures. On a previous thread, some of our fellow polycounters suggested that two things might be the reason: too low resolution geometry and bad uvs.

So, this time, I'm trying to really watch out for this.

Here is my question. I have a high resolution model with about 10 million polygons.
My lowest subdivision level is 2000 polygons. The second subdivision is 10k.

Even though the 2k model's silhouette holds up pretty well, is it enough? 
I'm considering deleting the 2k and make the 10k my new lowest and bake from it.

The problem is quality vs size... 10k for a head seems to be a little to poly expensive, but I can't afford to wash out the pores and wrinkles on this model.
What should i do?

Also, I included a picture of my Uvs just in case.

High res

Low Res

UV

AtticusMars

I'm really confused as to what you're trying to do here, wrinkles and pore detail are something that should be dealt with in the normal map, it doesn't matter how many polygons are in your low res mesh at that point, the only thing that matters is the resolution of your normal map and the high res mesh it was baked from.

LaurentiuN

You should make your low-poly based on silhouette of the high poly and nothing else. Don`t add geometry where wrinkles are or small details like Atticus saied. 
The 2k version looks good but you can optimize it even more. And for exemple you can add more geometry where the nose and mouth is and less geo to the top part of the head or behind the head.
Optimize by hand after you use zrmesher, if you used that.

huffer

I think there's a little confusion here - your low poly could be 500 triangles and look good with baked normal and texture.

I'm guessing in baking, your source is not the 10mil high poly, but the 10k? Or you're not baking textures, but projecting polypaint? Polypaint in Zbrush is practically vertex color, and if you don't have enough vertices, the polypaint will look blurred.

What you need to do, is export your 2k (or lower), your high poly (full 10 mil) and load them up in xnormal, and bake a normal map and a "Bake highpoly's vertex colors". Remember to disable "Ignore per-vertex-color" in your high mesh inside xnormal. You can then apply your baked normal and your baked vertex color (this is your diffuse) in Marmoset Toolbag or your software of choice; you should get the full details on your highres (something like 2k x 2k should be enough).

Kyle_butler

Thank you very much for clarifying this issue, AtticusMars, s1dK and huffer!

This misconception about the low res version was really an major issue on my models and polycount. 

Your answers really shed a light on this question for me. I always assumed that in order for the normal map hold and transfer the details from the high poly, the low one should have a considerable amount of details for the rays to cast properly.

Huffer, actually the hi res is 10m, and I have this two low-res options, the 2k and 10k. ( which I now know is irrelevant, once i kept the silhouette on the 2k one).

Thank you again for the thorough explanations!

Best regards!

LaurentiuN

Take a look at this WIKI page, has a lot of good info about low poly, normal maps etc http://wiki.polycount.com/wiki/Normal_map