Скачать или смотреть Smooth isosurface raytracing in real time

***Updated Video with 2x frame rate***:    • Smooth Isosurface Raytracing in Real Time  

Cleverly combining existing algorithms sometimes results in magic:
4D Perlin noise + marching-cubes + Snell's law + OpenCL parallelization

4D Perlin noise provides iso-values on a 3D Cartesian lattice. With the marching-cubes algorithm (http://paulbourke.net/geometry/polygo..., it is possible to generate triangulated isosurfaces from the lattice.
Turns out such a 3D lattice already is one of the ideal acceleration structures for raytracing. Any ray only has to check for possible intersections with iso-surface triangles contained within the traversed grid cells. This makes it run in real time on non-RTX GPU​s. Light rays from the camera traverse the lattice and check for intersections with the triangles that marching-cubes generates on-the-fly from the isovalues. Triangles never leave registers.

To get a smooth surface, I interpolate the surface normal vector: I first get the normals directly at the lattice points with gradient on the isogrid, then interpolate to get the normals at triangle vertices and interpolate again to where the ray intersects the triangle.