A quick and simple pass at procedurally texturing the afterburner. I say quick and simple, I've spent most of the day on it, predominantly trying to figure out how to get layered shaders to work with the Mental Ray renderer. I finally figured it out and put this together. It's a really simple spherical environment map blended with a standard 'granite' shader for rust. I did a quick automated UV mapping pass and then baked an Ambient Occlusion map to use as an alpha channel to blend the two. The idea being that the rust would sit in the recesses and the shiny chrome would be on upper, exposed areas and edges etc. It hasn't quite worked out that way but given how slapped together this is, I'm quite pleased with the way it looks.
I need to map the geometry properly to get a decent AO map from it that I can work into and make the distribution of the two procedural materials more realistic. I also need to work on the two procedural materials to make them a bit more convincing as well.
Something else I need to do is establish a texture scale. This is something I learned whilst working on Puss in Boots. It gives the textures on each surface a consistency and also gives you a fairly good uniform idea as to how close you can get to any given part of the model before it get's all soupy. The scale we used on Puss in Boots was, if I remember correctly, 512 pixels = 2 metres. Giving a pixel density of about 2.5 pixels per centimetre. That's pretty darn good but if the textures aren't tiled I'm going to end up with a load of VERY big textures which could get quite gruelling for the memory and the render times :/ I'll have to wing it, and I may well reduce the scale as I don't really ever intend rendering the ship up quite that close.