Issue with baking

Hello,

I’m having this issue when baking my lo & hi poly models.

I’ve seen the comments about the new extrude feature. (Even though i can’t quite figure out what it does it that helps… So i have played with it with some result but i still can’t get a good looking result - with always black spot appearing.

Note : My original hipoly sculp was a bit different on places, when i adjusted the topology i’ve also changed LIGHTLY the foot the ears and parts of the face.

I don’t now what i can do with what i have. My retopology was pretty high resolution as well compared to the courses ogre model, since my goal was mainly to learn for 3d animation for short films etc…

Is there ways to fix this, or should i retopologise the model with a lower polycount? current triangle counts is 90k.

Thanks for your help in advance!

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Hi, difficult to say what’s happening and why.

Some small comments upfront, to set things clear.

  • With Baking you mean what? As in baking Normal maps (High to Low poly), or Ambient Occlusion, etc.
  • I’ve seen the comments about the new extrude feature., you mean the new User Interface?
  • You have two objects visible in your screenshots. High and low poly. It doesn’t help to pinpoint the problems.

The black spots on your model are just black paint of your “Rabbit Cavity” diffuse map. This can happen when you unwrap the UV-mesh, paint the map (baking Cavity). Then changing (add/delete) the mesh without UV-mapping (again). But still, you reuse the diffuse map based on old mesh. The new mesh is now occupying space not painted. UV-mapping is an important process. So be sure your model is ready. If not the process starts over … I know everybody is eager to do the next steps. But good preparation is essential.

The “Rabbit Cavity” map can be placed in the color input. But it is not the way to use this type of map. You need to mix it with another ‘body’ texture shader.

When baking the IMAGE container node may not have any link (lines) to material nodes and must be selected (active) before you start baking a specific baking type.

First, check your UV-maps after modifying the mesh. Use the internal build-ingenerated type textures ‘UV-Grid’ or ‘Colour Grid’.

When baking AO-maps (cavity maps), you need to have a special lighting setup. If I’m remembering correctly, you don’t need low poly for this.

Don’t start a repo again. Check previous steps. But yes, things can go wrong badly. So always do a backup when destructive things. Or start a small side project to walk through all the steps on an easy model.

For animation, you do not need high poly models. Unless you want to have facial expressions close by. High poly models are only needed when there are many tiny details. Eye wrinkles, scars, etc. But they can be added also using handmade maps, this is what SubStance painter does with their library of stencils.

Let us know if you are making progress here. And provide more specif info.

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I do not believe there is any need to retopologise. Put simply If the lower poly mesh is outside the higher poly Blender ‘beams out’ the data of the map type until it hits the low poly and ‘paints’ the new map of the low poly.

The problems originate from the low poly being inside the high poly in some places. Blender effectively looks inside the low poly for the pixel info to paint and finds nothing as it is on the outside! So paints, black, nothingness.

So ray distance, and this new extrusion I guess I have not used it yet, are ways of starting the ‘beaming’ further back, outwards, beyond the outside of the low poly so it starts looking for the data to paint on actually outside the low poly mesh. How high these need to be set will vary by every model, and it’s fit to the high poly.

Hence so much advice is ‘tweak the ray distance’. It is not usually a matter of press this button or use this number and it will work. Sadly.

My understanding of the baking issue. Baking the colour of the red cube (half cube ok) to the Icosphere would result in a map being created that would make the right one look like that when used.

4 Likes

Hi

Good advice above…

So, your model is not symmetrical? Another thing to double-check:
If you used a mirror modifier for the retopologised mesh, you need to add another shrink-wrap modifier at the end of the chain (i.e. make sure the shrink-wrap isn’t the 1st modifier). Alternatively, apply the mirror, then do tweaks with a shrink-wrap modifier, then apply that.

This will ensure the asymmetry will get wrapped and you should get a more consistent bake.

Good luck.

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Just noticed there is a similar well done and featured answer in the Udemy Q&A

A Possible Solution for Normal/Cavity Map Errors.

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