Export Collada Blender Cycles Textures?

[Morris Venenbaum]

Hello,

 

I have created a metal like material in the node editor and rendered it with the cycles renderer.

However, the Collada export doesnt seem to consider this metal material.

Is there a way to use cycles with the collada export?

I dont want to use standalone textures to import in SL.

 

[Christhiana]

The way to go here is to bake the diffuse, normal and specular maps in blender and then import them into SL seperatly from your model. Then reapply them in SL.

[Drongle McMahon]

I dont want to use standalone textures to import in SL.

May I ask why not? There are several disadvantages of uploading with the model, which I have listed before.

Making good metallic effects is quite hard. This is especially the case if you want something that will work with and without advanced lighting. You really need to use normal and specular maps for advanced lighting. If the metal is smooth, you can get away with using the blank versions of these. Using the diffuse map (if you have one) as specular map sometimes works better, as the colour of specular reflection from metals is the same as the diffuse colour. For more realistic metal, you need to make these maps. As far as I know, you can't upload normal and specular maps with the model. So you are going to have to upload separate textures unless you stick to the blank maps.

Here is one of my attempts to make something metallic, gold and silver. The maps here were not baked. They were all made by manipulating the diffuse texture in Gimp. One quarter shown here, as they are symmetrical. Unless your metal is smooth, I think it is essential to use the alpha channels of the normal map (specular exponent) and the specular map (environment reflection). Otherwise you get the overall glazed/wet look. You can experiment with the Glossiness and Environment slider values which have strong effects, but do that with different lighting conditions, because their effects are very dependent on them.

Here is a prim cylinder with these maps inworld. Top row is default lighting at 3pm. Advanced lighting on at the left and off at the right. In the bottom row, advanced lighting is on and a light source (not projected*) is added at the lower left; 3pm on the left. midnight on the right.

You can bake normal and specular maps from cycles. I have not baked normal maps in cycles, only with the blender render. So I can't comment on that. For the specular map, use the Glossy color bake, which just does the reflectiveness of the surface. The other Glossy bakes are for highlights, which depend on the lighting. They also bake what a camera looking back along the normal would see at each point, which does not correspond to any real camera view. Unfortunately, these bakes will not give you the separated specular exponent (inversely related to roughness) of the separate environmental reflection map, which you need for the best results. I have tried to get these maps from baking the roughness parameter as if it were a colour, but not met with much success. Then you still have to put them together in Gimp/PS. Maybe someone has worked this out?

I also tried to make a node setup that would mimic the SL lighting in Blender, using the alpha channels as in SL, but I couldn't find hoe to get the environmental reflection to work. That would be very useful. Meanwhile, testing the maps in Blender, as Cristhiana said, is the best you can do. Then use local textures to experiment, so that you don't waste upload fees.

*note: projected lights are also included in the environmental reflection. There's a problem with this in the current viewer. but a tested fix is on the way. Then they should make good metallic effects.