static mesh lighting not taking into account surrounding objects

Development Rendering
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1

Hi there,

So I’ve been trying to make a demo product with a model of a skull that has several cut-away parts so that the user can view nerves that run through or behind the bones. I’ve made these models in 3ds Max, where they fit perfectly. I’ve tried several different methods but I’m getting seriously bad results with the lighting no matter how I do it, as shown below.

101218-skulllighting.png
101218-skulllighting.png536×620 147 KB

The methods I’ve tried so far are:

  1. Exporting on standard settings with a 2nd channel lightmap, no AO, smoothing groups turned on.
  2. Exporting with edited normals and one and two UV channels, but this turns off smoothing.
  3. Exporting with no lightmaps generated but with an AO map.
  4. The product is meant for mobile so static lighting is a must; I’ve tried to set the model to static and kept it moveable but with ‘light as static’ turned on.
  5. ‘Cast Shadows’ set to both true and false.
    Plus pretty much every combination of the above you can think of.

For example, on the jaw; its like lightmass isn’t taking into account the model of the jaw surrounding the cut-away section, which is a different model and instead just picking up the sharp edge of the model itself. Any ideas anyone?

2

I don’t completely understand what you want exactly, could you maybe show an example what you want? :slight_smile:

Maybe you could put your skull material to unlit and bake all the lighting on the texture so you don’t need any lights in your scene.

Also take a look at the unreal PBR materials!

3

Here are some things to check:

  • Check your Lgihtmap resolution and make sure it’s high enough to support the quality shadowing your want.
  • Use the Lightmap Density visualization to make sure that you’ve got a consistent sizing between pieces for the lightmap bake. Otherwise this can throw off the shading between them. Viewport > Viewmode > Optimization > Lightmap Density
  • Make sure you have properly setup lightmaps for each separate mesh.
4

Hi Tim,

So, I’ve had chance to have a look at this again in and around other things; I’ve improved the look to degree by raising the lightmap resolution; some of them got very silly before there was any real effect though. The most complex model has a lightmap resolution of 512x512, which just seems crazy huge to me; most of the others are 64x64.

102283-skulllighting1.png
102283-skulllighting1.png731×664 232 KB

I’m still having problems with some areas; mostly behind the eye socket. You can clearly see a portion where the lighting isn’t matching up. There’s also a strange black feathered shade around the inside bit of the jaw. All the models have been UV mapped and light mapped the same way. The lighting is all set as static. Any ideas?