Compressed ray direction data in a ray tracing system

Abstract

Ray tracing systems process rays through a 3D scene to determine intersections between rays and geometry in the scene, for rendering an image of the scene. Ray direction data for a ray can be compressed, e.g. into an octahedral vector format. The compressed ray direction data for a ray may be represented by two parameters (u,v) which indicate a point on the surface of an octahedron. In order to perform intersection testing on the ray, the ray direction data for the ray is unpacked to determine x, y and z components of a vector to a point on the surface of the octahedron. The unpacked ray direction vector is an unnormalised ray direction vector. Rather than normalising the ray direction vector, the intersection testing is performed on the unnormalised ray direction vector. This avoids the processing steps involved in normalising the ray direction vector.

Description

Background technique [0001] A ray tracing system can be configured to render images from a 3D scene description. Images can be photorealistic, or to achieve other goals. For example, animated movies can be produced using ray tracing systems. Ray tracing technology simulates the natural interaction of light with objects, and complex painted features can naturally arise from tracing the rays of a 3D scene. Because pixels are usually processed independently of each other, ray tracing can also be parallelized relatively easily on a pixel-by-pixel level. Ray tracing allows photorealistic images to be drawn, but often requires high levels of processing power and large working memory, which makes ray tracing potentially difficult to render images in real time (for example, for gaming applications), especially on silicon area, On devices where cost and power consumption have strict constraints, such as on mobile devices (eg, smartphones, tablets, laptops, etc.). [0002] A ray tra...

AI Technical Summary

Problems solved by technology

Therefore, a large memory may be required to store ray data, which may be disadvantageous in terms of silicon area usage and cost of the ray tracing system

Also, writing ray data into memory, and reading ray data from memory consumes power and time, so a large amount of ray data may lead to increased power consumption and latency of the ray tracing system

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