deepshade hints and tips

crusty metal shader

Its simple but results are disproportionally good for the amount of work. In Photoshop make a grayscale fractal type image (1K X 1k)save as TGA In XL make a simple surface sphere(48). Call this outershell Make a duplicate of this sphere, call it Middleshell, uniformly scale this to be very very very slightly smaller then Outershell. Make a duplicate if Middleshell and call this object inner shell. Once again scaleit by hair amount. Make a new material and set it up as weathered metal, using the map just painted andnoise 2d textures. You can use any fields EXCEPT GERNLOCKING on this first material. Call this material INNER.

Copy/Paste to make a duplicate of this material, call this material OUTER. In this OUTER material add the fractal gray map you painted in PS as a Genlock map. Go back to Photoshop and mirror/rotate the gray map and save it as MAP2(or any other name). Back to XL. Make a copy of OUTER material and call it MIDDLE. Replace the first Genlock map with Map2. Apply INNER material to Innershell Apply MIDDLE material to Middleshell Apply OUTER to the OUTERSHELL It is important that all materials are applied using same mapping coordinates. What will happen is that when rendering, the fractal grayscale map will etch away pixels exposing geometry within. You can have as may “crust” layers as you wish.

The beauty of this is that the outer crust edges will cast shadows on inner ones creating a very realistic illusion.If the scaling was very small, antialising should prevent rendering artifacts. It may be a good idea to link the two objects to the third one for ease of animation. If anyone has good results with this technique, let us know. Maybe include a URL. BTW, I made a fractal gray map, using some PRMAN shaderwriting. If anyone wants it just e-mail me and I’ll send you the JPG.

David Rindner

tips ref number

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