• Alien vs. Triangles is a study in using tessellation on a dynamic animating character.
• Tessellation is most commonly used to add geometric complexity in a detailed area of a surface. Our Alien demonstrates this, but goes far beyond just adding detail to a static surface. Several displacement maps are associated with the surface of the Alien which completely change his look on command, and allow for realistic surface damage as you blast him with a laser.
• Character skins – The Alien has three “skins” – Normal, Spike and Fungus. Each of these is a separate displacement map, with associated textures and shaders. Once “infecting” the Alien with a different skin type, you can watch as the new displacement grows across his skin transforming him into a very different looking character.
• Damage layers – The Alien also has four displacement maps that are used as damage layers. These layers are at different levels above and below his skin, and are exposed as he his shot by a laser. These levels include a blister layer that’s above his skin, and three levels of muscle and guts layers at successively deeper levels beneath the skin. Once shot, these layers are procedurally exposed and interpolated to create a nasty gaping open wound.
• We are calling this "multi-dimensional tessellation" because we can vary seamlessly between the tessellation and displacement of 3 character skins and 4 damage layers resulting in a character that feels "solid" or "volumetric."
• This is a great example of how the tessellation horsepower of GeForce GTX 500 GPUs not only allow for surface detail in things like mountainous terrain, but add realism and interest to the skinned surface of animated characters.