Cone tracing
Encyclopedia
Cone tracing is a derivative of the ray tracing algorithm
that replaces rays, which have no thickness, with cones. Cone tracing is related to beam tracing
, but uses circular rather than polygonal cross sections.
Cone tracing solves certain problems related to sampling and aliasing
, which can plague conventional ray tracing. However, cone tracing creates a host of problems of its own. For example, just intersecting a cone with scene geometry leads to an enormous variety of possible results. For this reason, cone tracing has remained mostly unpopular. In recent years, increases in computer speed have made Monte Carlo
algorithms like distributed ray tracing
much more viable than cone tracing.
However, a recent SVO
implementation by Crassin et al has shown remarkable promise, demonstrating global illumination of remarkable quality at 25-70 frames per second.
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
that replaces rays, which have no thickness, with cones. Cone tracing is related to beam tracing
Beam tracing
Beam tracing is an algorithm to simulate wave propagation.It was developed in the context of computer graphics to render 3D scenes,but it has been also used in other similar areas such as acoustics andelectromagnetism simulations....
, but uses circular rather than polygonal cross sections.
Cone tracing solves certain problems related to sampling and aliasing
Aliasing
In signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable when sampled...
, which can plague conventional ray tracing. However, cone tracing creates a host of problems of its own. For example, just intersecting a cone with scene geometry leads to an enormous variety of possible results. For this reason, cone tracing has remained mostly unpopular. In recent years, increases in computer speed have made Monte Carlo
Monte Carlo method
Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...
algorithms like distributed ray tracing
Distributed ray tracing
Distributed ray tracing, also called distribution ray tracing and stochastic ray tracing, is a refinement of ray tracing that allows for the rendering of "soft" phenomena....
much more viable than cone tracing.
However, a recent SVO
Sparse voxel octree
A sparse voxel octree is a 3D computer graphics rendering technique using a raycasting or sometimes a ray tracing approach into an octree data representation....
implementation by Crassin et al has shown remarkable promise, demonstrating global illumination of remarkable quality at 25-70 frames per second.