I have an idea about where to go from now regarding the textures and light system we have in place.

I'd like to propose to make it possible to define a custom shader (slice) for each texture, i.e. the engine would test if there is a file called lava_red.c in the Material.ocg next to the lava_red.jpg, if there is, the shader is applied for this texture.
This'd create a straightforward framework to make many (slightly) different shaders for all the different kinds of textures¹ and would remove the necessity to define shader parameters in the OCM material definition and thus also remove the necessity that shaders like the shiny gold be implemented centrally.

Reason:
When I looked at Hideout.ocs, I noticed that the shiny effect of the gemstones cannot be applied to the background gemstones. Why? Because I have to specify those shininess parameters in the OCM material definition and not per texture. And the material is Tunnel - I do not want the normal tunnel to shine. Of course there is a workaround for that - simply create an own material for the background gemstones.

But that fact made me contemplate about what belongs to a texture definition and what belongs to a material definition. I think the best definition is that the material definition defines the behaviour of the material in the game world while the textures define the visuals of the material, how it looks like. But the shininess of the material is something visual, so I guess it is only in the OCM because there is not such a thing as a texture definition file.

What do you think of that? Do you think it is technically feasible?

¹ lava noise, firestone glow, bubbles in the acid, wavy reflection-things in the water, ...