Abstract
A method for representing solid matter as small primitives and drawing them without triangle meshes. Each primitive (a physel) is a 32-byte record holding its position, rotation and half-sizes in its object's frame; four shape dials (two roundness exponents, a taper and a bevel) that select one shape from a single superquadric equation; two material identifiers and a blend; and a tint, a seed and flags. Every consumer evaluates the same exact shape: closed-form intersections for boxes, frustums, ellipsoids, cylinders and cones, Newton steps on exact distances for bevelled shapes, and for the rest a guarded Newton step that can never pass the surface. To draw, each visible physel's screen-space rectangle is rasterized and each covered pixel casts one exact ray, writing exact depth and the physel's index into a visibility buffer; shading then runs once per pixel. Physels are culled in chunks of up to 64 in two rounds against a depth pyramid, and distant chunks are replaced by a few fitted boxes only while their error stays under half a pixel.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Kimberlin, Kyle, "Physels Superquadric Shape Drawn by One Exact Ray Cast Per Pixel for 3D Computer Graphics and Physical Simulation", Technical Disclosure Commons, ()
https://www.tdcommons.org/dpubs_series/12432