Projective Displacement Mapping for Ray Traced Editable Surfaces

TL;DR

This paper introduces a real-time ray tracing method for complex, editable surfaces using projective displacement mapping, which improves quality and speed over existing techniques without requiring dynamic acceleration structure rebuilding.

Contribution

It presents a novel direct sampling approach for displaced surfaces that enables real-time editing and rendering without dynamic acceleration structure updates.

Findings

Faster than comparable methods for ray tracing

Improved surface quality with smoothed normals and tight bounds

Supports real-time surface editing

Abstract

Displacement mapping is an important tool for modeling detailed geometric features. We explore the problem of authoring complex surfaces while ray tracing interactively. Current techniques for ray tracing displaced surfaces rely on acceleration structures that require dynamic rebuilding when edited. These techniques are typically used for massive static scenes or the compression of detailed source assets. Our interest lies in modeling and look development of artistic features with real-time ray tracing. We demonstrate projective displacement mapping, a direct sampling method without a bottom-level acceleration structure combined with a top-level hardware BVH. Quality and performance are improved over existing methods with smoothed displaced normals, thin feature sampling, tight prism bounds and ray-bilinear patch intersections. Our method is faster than comparable approaches for ray tracing, enabling real-time surface editing.