My model loses a lot of detail from zbrush to real time. Normal problem (uv, baking or mesh?)

Kyle_butler

Hi guys! I've read the normal map thread but i can't really get what is wrong with my model...

I've got quite a lot of detail on zbrush, but after exporting the normal maps with xnormal, my mesh gets washed out... i just wanted to know if this kind of problem is the common (since the amount of polygons is significantly reduced) or if I'm making something wrong...

For instance, is there a proportional reduction ratio to the amount of polygons of the high mesh to the low? If My model is 200k on high, the low shoulld be 200?

Take a look at the high model and normal maps and, if you may, tell me what is wrong:

Shirt




Shoe Lace





The low poly version is on sketchfab. 
https://sketchfab.com/models/377ddfcaec0646fd9c7f58d6a12fe057

You see? washed out details... Is it the auto uv maps that are incorrect, the low poly version that is to loow to genarate a good enough normal map, some mistake while baking...

Thanks!

jfitch

Yeah those UVs aren't really going to help you get the results you're looking for. I would spend some time making them look as good as possible and make sure that there's as little dead space (non-island space) as possible. It looks like those are repeating patterns, so you could also get away with using a shader that tiles a detail normal map, but your UVs would have to be set up appropriately for that as well. Also, what resolution are your textures at, and what are you using to bake?

Kyle_butler

I don't know how to create a normal map tile, that you mentioned.
Do you have a resouce or example on this? 

Also, could you show me a good uv setup example?

I'm baking using xnormals and the texture of the shirt is 1k and the shoe lace is 512x512.

skankerzero

There simply isn't enough pixels in your texture to capture the microdetail.

As Jfitch said, you need to tile the microdetail onto your texture through the shader if you can't have higher resolution textures.

Unfortunately, it's difficult to provide a good example for a 'good' uv layout since uvs are so specific per model. Generally with shirts, you can run the uv seam down the actual seams of the cloth. You split the torso into a front and back. The sleeves you can run the seam down the underside and unfold them like cylinders.
Basically think of the uvs as an actual cloth pattern. Unwrap it like the cloth patterns real clothing is made of before sewn together.

Kyle_butler

Thanks a lot for your answer SKANKERZERO . Besides the uv like real cloth patter (wich is a great advice) , do you recommend me to bake the map with 4k or even higher for the microdetail?

kodde

Another common option is to make the micro features a bit bigger to be able to represent them with your texture budget.

RTS games for instance take this to extremes even with geometry to be able to show key features at the desired distance.

Kyle_butler

Thanks, Kodde! I'll try that also. Btw, since you mentioned the geometry. If i increase the polycount, will i get more detail on the output normal map? 

ZacD

Kyle_butler said:

If i increase the polycount, will i get more detail on the output normal map? 

No.

You might want to watch this, It's about how Epic Game's Paragon textures their characters. https://youtu.be/toLJh5nnJA8?t=4189

1 hour 10 minutes if the link doesn't skip ahead.

Kyle_butler

Thanks a lot, ZACD. I might watch the whole thing altogether.