VK_RAYTRACE

This project is a glTF 2.0 sample viewer using Vulkan ray tracing. It follows the ray tracing tutorial and combines all chapters into a single example.

The lighting equation is based on:

• glTF PBR reference implementation from Khronos.
• Disney PBR

The rendering pipeline can be switched from:

• Ray Tracing Pipeline: RayGen, Closest-Hit, Miss, Any-Hit model
• Ray Query: Compute shader using Ray Queries

Features

• Load glTF 2.0 files ascii and binary using tiny glTF
• Support for full node hierarchy
• Full implementation of metallic-roughness and specular-glossiness
• IBL lighting using importance light sampling
• Alpha blend and cut-out
• Texture transforms and samplers

Attributes

• Normal : create geometric normal when not present
• Texture coords : only set 0, project cube map when text coords are missing.
• Tangents : generate tangents and bitangent when missing.
• Color : default (1,1,1,1)

Extensions

• KHR_lights_punctual (some support)
• KHR_materials_pbrSpecularGlossiness
• KHR_materials_clearcoat
• KHR_materials_unlit
• KHR_texture_transform
• KHR_materials_anisotropy
• KHR_materials_transmission
• KHR_materials_sheen (some support)

Usage

Controls

Action	Description
LMB	Rotate around the target
RMB	Dolly in/out
MMB	Pan along view plane
LMB + Shift	Dolly in/out
LMB + Ctrl	Pan
LMB + Alt	Look around
Mouse wheel	Dolly in/out
Mouse wheel + Shift	Zoom in/out (FOV)
Space	Set interest point on the surface under the mouse cursor.
F10	Toggle UI pane.

Change glTF model

• Drag and drop glTF files (.gltf or .glb) into viewer

Change HDR lighting

• Drag and drop HDR files (.hdr) into viewer

Setup

git clone --recursive --shallow-submodules https://github.com/nvpro-samples/nvpro_core.git
git clone https://github.com/nvpro-samples/vk_raytrace.git

Other

Tags:

• raytracing, GLTF, HDR, tonemapper, picking, BLAS, TLAS, PBR material

Extensions:

• VK_KHR_RAY_QUERY_EXTENSION_NAME
• VK_KHR_RAY_TRACING_PIPELINE_EXTENSION_NAME
• VK_KHR_ACCELERATION_STRUCTURE_EXTENSION_NAME
• VK_KHR_SHADER_CLOCK_EXTENSION_NAME
• VK_KHR_MAINTENANCE3_EXTENSION_NAME
• VK_KHR_PIPELINE_LIBRARY_EXTENSION_NAME
• VK_KHR_DEFERRED_HOST_OPERATIONS_EXTENSION_NAME
• VK_KHR_BUFFER_DEVICE_ADDRESS_EXTENSION_NAME
• VK_EXT_SCALAR_BLOCK_LAYOUT_EXTENSION_NAME
• VK_EXT_DESCRIPTOR_INDEXING_EXTENSION_NAME
• VK_KHR_GET_MEMORY_REQUIREMENTS_2_EXTENSION_NAME
• VK_KHR_DEDICATED_ALLOCATION_EXTENSION_NAME
• VK_KHR_SWAPCHAIN_EXTENSION_NAME
• VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME
• VK_EXT_DEBUG_UTILS_EXTENSION_NAME
• VK_KHR_SURFACE_EXTENSION_NAME

Links

• glTF format specification
• glTF Sample Models
• tiny glTF library
• Ray Tracer Tutorial

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Test Scenes

Model	Link
	2 Cylinder Engine
	Alpha Blending
	Anisotropy
	Antique Camera
	Boom Box
	Carbon Fiber
	Clear Coat
	Corset
	Damaged Helmet
	Flight Helmet
	Metal Rough Spheres
	Punctual Light
	SciFi
	SpecGlossVsMetalRough
	Unlit
	Transmission
	Box Vertex Color