Stargazing: Rocks

Week 11

Getting the form, lighting and texture in 3D to fit the style which we wanted took a lot longer than anticipated. This is the aim which I wrote out for myself when I started:

“Make the rocks so matched to the painting that it would be impossible to tell that they were 3D if you composited them side by side into the painted concept. But, don’t let the concept dictate all, feel free to develop and improve when the opportunity arises.”

I started by taking the blocked proportions of the dolmen into Mudbox for sculpting. Although rock seems like a simple thing to sculpt it took me a while to get suitable forms. My first attempt was too rough and digital-clay like and looked even worse  when I tried to render the detail with a displacement map in Maya’s software renderer.

I looked up how to improve maya software displacement map settings but discovered that Mental Ray is a wiser choice for displacement maps.

I worked on a single rock, modified in Mudbox, for a while to see if I could achieve the style. I tried making very hard edged light by adjusting the intensity of a directional light. To create the fine carvings, I first tried using the knife tool in Mudbox but this gave me very lumpy results even after using the smooth and scrape tools. I also tried using the freeze tool but couldn’t create the desired results. I found that making a displacement map in Photoshop with a hard edged brush gave a much cleaner result and also maintained the smaller detail of the brush’s edge. The depth of this could then be increased by adjusting the alpha gain of the image file so as to make deeper shadows. By adding a few edge loops I could make hard rock edges without too much resolution and I tried bump mapping a canvas texture to see what this detail could look like.

From talking to Clare I was directed to look at the ramp shader with shading set to light direction and interpolation set to linear. From going through the ramp shader attributes I found that I could make the shading even more graphic like the painting if I cast the scene in shadow with a box and used the shadow colour to control the light colour and the incandescence to control the shadow colour.

The depth of the bump map, made from painted/canvas texture, controlled the detail on the interface between shadow and light giving a painted/dry brush edge to this area.

To create the rock shapes, I imported my blocked versions from Maya into Mudbox as these had roughly the silhouette and volume that I needed. I made the mistake of spending time UV unwrapping my modified boxes as I thought I would be applying maps onto them. As simple as they were, they still took time to unwrap using planar mapping as there were a few of them. Instead of importing the Mudbox sculpted detail as maps I ended up importing the level 1 subdivision of my rocks as .obj files into Maya and re-unwrapping them. Simple silhouettes were all that I needed but it might have been faster to figure out how to combine my Mudbox map and Photoshop map for applying as one map onto my first boxes.




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