Files
UnrealEngineUWP/Engine/Shaders/Shared/RayTracingDefinitions.h
Yuriy ODonnell ed3704b89a Reserve a ray mask bit for excluding objects from scene capture views
[CL 15867358 by Yuriy ODonnell in ue5-main branch]
2021-03-30 16:11:25 -04:00

55 lines
3.5 KiB
C

// Copyright Epic Games, Inc. All Rights Reserved.
/*================================================================================================
RayTracingDefinitions.h: used in ray tracing shaders and C++ code to define common constants
!!! Changing this file requires recompilation of the engine !!!
=================================================================================================*/
#pragma once
// Change this to force recompilation of all ray tracing shaders (use https://www.random.org/cgi-bin/randbyte?nbytes=4&format=h)
// This avoids changing the global ShaderVersion.ush and forcing recompilation of all shaders in the engine (only RT shaders will be affected)
#define RAY_TRACING_SHADER_VERSION 0x7c6a2787
#define RAY_TRACING_REGISTER_SPACE_LOCAL 0 // default register space for hit group (closest hit, any hit, intersection) shader resources
#define RAY_TRACING_REGISTER_SPACE_GLOBAL 1 // register space for ray generation and miss shaders
#define RAY_TRACING_REGISTER_SPACE_SYSTEM 2 // register space for "system" parameters (index buffer, vertex buffer, fetch parameters)
#define RAY_TRACING_MASK_OPAQUE 0x01 // Opaque and alpha tested meshes and particles (e.g. used by reflection, shadow, AO and GI tracing passes)
#define RAY_TRACING_MASK_TRANSLUCENT 0x02 // Opaque and alpha tested meshes and particles (e.g. used by translucency tracing pass)
#define RAY_TRACING_MASK_THIN_SHADOW 0x04 // Whether the thin geometry (e.g. hair) is visible for shadow rays
#define RAY_TRACING_MASK_SHADOW 0x08 // Whether the geometry is visible for shadow rays
#define RAY_TRACING_MASK_SCENE_CAPTURE 0x10 // Whether the geometry is visible when rendering scene capture views
#define RAY_TRACING_MASK_ALL 0xFF
#define RAY_TRACING_SHADER_SLOT_MATERIAL 0
#define RAY_TRACING_SHADER_SLOT_SHADOW 1
#define RAY_TRACING_NUM_SHADER_SLOTS 2
#define RAY_TRACING_MISS_SHADER_SLOT_DEFAULT 0 // Main miss shader that simply sets HitT to a "miss" value (see FMinimalPayload::SetMiss())
#define RAY_TRACING_MISS_SHADER_SLOT_LIGHTING 1 // Miss shader that may be used to evaluate light source radiance in ray traced reflections and translucency
#define RAY_TRACING_NUM_MISS_SHADER_SLOTS 2
#define RAY_TRACING_LIGHT_COUNT_MAXIMUM 256
#define RAY_TRACING_MAX_ALLOWED_RECURSION_DEPTH 1 // Only allow ray tracing from RayGen shader
#define RAY_TRACING_MAX_ALLOWED_ATTRIBUTE_SIZE 8 // Sizeof 2 floats (barycentrics)
#define RAY_TRACING_MAX_ALLOWED_PAYLOAD_SIZE 64 // Our maximum allowed payload size (sizeof FPackedMaterialClosestHitPayload)
#define PATHTRACER_MAX_RECT_TEXTURES 8
#define PATHTRACER_COHERENT_TILE_SHIFT 3
#define PATHTRACER_COHERENT_TILE_SIZE (1 << PATHTRACER_COHERENT_TILE_SHIFT)
// Constants for the 'Flags' field of FPathTracingLight
#define PATHTRACER_FLAG_LIGHTING_CHANNEL_MASK (7 << 0) // Which lighting channel is this light assigned to?
#define PATHTRACER_FLAG_TRANSMISSION_MASK (1 << 3) // Does the light affect the transmission side?
#define PATHTRACER_FLAG_NON_INVERSE_SQUARE_FALLOFF_MASK (1 << 4) // Does the light have a non-inverse square decay?
#define PATHTRACER_FLAG_STATIONARY_MASK (1 << 5) // Only used by GPULightmass
#define PATHTRACER_FLAG_TYPE_MASK (7 << 6)
#define PATHTRACING_LIGHT_SKY (0 << 6)
#define PATHTRACING_LIGHT_DIRECTIONAL (1 << 6)
#define PATHTRACING_LIGHT_POINT (2 << 6)
#define PATHTRACING_LIGHT_SPOT (3 << 6)
#define PATHTRACING_LIGHT_RECT (4 << 6)
#define PATHTRACER_FLAG_CAST_SHADOW_MASK (1 << 9)