Name		Name	Last commit message	Last commit date
parent directory ..
docs		docs
shaders		shaders
CMakeLists.txt		CMakeLists.txt
README.md		README.md
mm_opacity.cpp		mm_opacity.cpp
mm_process.cpp		mm_process.cpp
mm_process.hpp		mm_process.hpp

README.md

Opacity Micro-Map in Vulkan

Overview

This sample demonstrates the implementation of Opacity Micro-Maps in Vulkan for efficient ray tracing.

Key Concepts

Encodes visibility for triangle sub-regions
Triangle classification: opaque (blue), transparent unknown (red), transparent (invisible)
Selective AnyHit shader invocation based on opacity state

Implementation Details

Micro-Triangle Generation

4^subdivision triangles per subdivision level
Barycentric coordinate mapping using BirdCurveHelper::micro2bary
World position projection for radius-based classification

Data Structures

Value Buffer: 2-state (1-bit) or 4-state (2-bit) opacity encoding
VkMicromapTriangleEXT Buffer: Maps triangles to value buffer data
Index Buffer: Continuous array for VkMicromapTriangleEXT indexing
VkMicromapEXT: Constructed from above data

BLAS Integration

VkAccelerationStructureTrianglesOpacityMicromapEXT attachment
Linked via pNext of VkAccelerationStructureGeometryTrianglesDataKHR

Opacity-MicroMap-SDK

Features

Automated asset conversion for ray tracing optimization
Texture and geometry analysis
Runtime or offline processing capabilities
CPU and GPU conversion options

Integration

Compatible with various ray tracing applications
Flexible API for pipeline integration
Supports diverse hardware and software configurations