Next, I modified the geometry, experimenting with the deformation tools (Tool>Deformation). There was no exact science to get the right look but I used the size, inflate and smooth deformers the most. I also inverted the mask and played with negative values in the deformers as well. Here's a Zbrush render with some of the final chunks done:
Once I was happy with my detailed chunks, I created a new texture with a size of 2048 or 4096 depending on the scale of the object, with a color of 50% grey. Then it was onto Zmapper. In Zmapper, I loaded the 3dsmax's setting for best quality tangent space, and adjusted the scan distance max range an average 40% above the default. After generating the normal map, Zmapper kicks you back to the main Zbrush window with what looks like a screwed up transfer. It's actually 100% ok and will look correct once you save out the texture (normal map) from zbrush and apply the map in 3dsmax. Finally, I exported out subdivision 3-4 for each chunk out of Zbrush and replaced the base models in 3dsmax with higher poly versions. Here's an image of the chunks back into 3dsmax, color coded. You can see the vines in the scene which were created using 3dsmax's hair plug-in on renderable splines with some noise. They would later be rendered separately with some grass in a pass along with their shadows.
Texturing and Materials for the Cave
My texturing process was split up in two stages. The first stage was constructing the base color texture. Then I used that base in Zbrush to aid in my normal map creation.
For creating my base textures I used the awesome 3D Total Textures. Specifically for the textures in the cave, Vol . 1 and Vol . 12 were used. I used basic Photoshop techniques to blend and adjust the textures to get a consistent base for all chunks. Below is an example of the texture breakdown for the "hole" chunk: