Dungeons and Darkness and 32-Bit Displacement! Oh, my!

This week was both a battle and a huge learning experience for me.  I was unsure as to how I was going to accomplish the high resolution details in this scene.  At first, I decided to go with Mudbox for the high-resolution sculpting so I could do the color and bump maps at the same time.  However, I the performance of Mudbox on my system still leaves me wanting better results.  In addition, the camera controls in Mudbox are kind of screwy and I have had many times where I couldn't find my model to start sculpting.

So I hopped back into ZBrush to do the high resolution sculpting.  This was going to be an interesting challenge because I haven't had that much experience with getting things from ZBrush back to Maya.  Mainly it's been rendering from within ZBrush.  This also meant learning about 32-bit displacement maps and how to set them up properly within a scene.

There were lots of iron fixtures and pieces that I put in the chamber and I didn't really feel like I needed to put fine painted detail on them since they weren't going to be the central piece of the scene.  I decided instead to use a set of 3D procedural textures to get the look I was going for.  In this dark scene, I think it will work just fine.

To get the super fine details within the rock and bricks, I had to use a combination of normal maps and displacement maps.  A normal map is typically used for the bump map details on your model, basically as a way to fake tiny details jutting out from your surface.  A displacement map actually pushes or pulls your geometry in or out accordingly, depending on what data is in the image file.  I had a hard time figuring out how to render out 32-bit displacement maps from ZBrush, mainly because of the confusing way in which I was using the Multi-Map Exporter plug-in.  At first my displacement maps were very subtle, then I realized that I was using the wrong subdivision level in ZBrush to calculate the displacement map from. Once I got that straightened out, the rest was a piece of cake.

Mental Ray does render-time subdivision and displacement through a little feature called the approximation editor.  Essentially, when the computer goes to render, it analyzes the displacement map to find where the most "movement" will occur within the model.  It then takes the low-resolution geometry and subdivides it only where it really needs it.

Overall, I am pleased with the way this is turning out.  With just the lighting, normal maps, and displacement maps, things are really starting to stand out.  It will be a bugger to render, and I hope that Maya can handle it all.  This will make a nice addition to my reel.

For kicks I rendered out an image with Final Gather turned on.  You can see how the lighting won't be so dark the added bounce diffuse lighting.  There will be some tricky hurdles ahead like adding light fog and some Maya fluids for the torch flames, but I hope I can get it all worked out.  So far, the learning experience has been very valuable.

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