FeiRays

Reusable Vulkan based ray-tracing code base.

The code is evolved from VkRayTraceWeekend.

Here, I'm trying to make it more extendable and reusable, so I can have more fun with it.

Now playing with McGuire Computer Graphics Archive

The "sponza" model, 900x600x1000 rays, rendered in 11.2 seconds using RTX 2060 super.

The "breakfast_room" model, 900x600x1000 rays, rendered in 18.4 seconds using RTX 2060 super.

A Python frontend can be found in the "python" folder.

Using the Python frontend, the above case can be rendered using the following Python script:

import FeiRays

scene = FeiRays.Scene(900, 600)
scene.add_sunlight((1,1,1), 2, (4000,4000,4000))

transform = FeiRays.Transform()
scene.add_wavefront_object(transform, "breakfast_room", "breakfast_room.obj")
scene.set_camera((2.5,1.5,2.5), (0,1.5,0), (0,1,0), 45)
scene.trace(1000, 50)

img = scene.get_image()
img.save("breakfast_room.png")

(It is assumed that the model file "breakfast_room.obj" is located in the folder "breakfast_room".)

The Python frontend (prebuilt for Win64 and Linux64) can be fetched from Pypi:

# pip install FeiRays

Building and Running

Building the project is simple.

Volk and Vulkan-Headers are included as submodules, so it should be fine to build without Vulkan SDK. But be sure to have a driver that supports Vulkan 1.2. Nvidia users should use one of the "beta" drivers from https://developer.nvidia.com/vulkan-driver.

• Clone the repo and update the submodules
• Use CMake to generate a VS solution at FeiRays/build.
• Build and run the tests.
• Shaders (spv) are expected at ../shaders relative to the starting folder.

License

I've decided to license this project under '"Anti 996" License'

Basically, you can use the code any way you like unless you are working for a 996 company.

Progress

In case someone is interested in the progress of the project, here is a list of what have been implemented so far.

Random Number Generator for Shaders

For monte carlo path-tracing, it is quite essential to have a pseudo-random number generator ready everywhere. For this purpose, we have a minimal set of XORWOW implementation of CURAND ported here.

Vulkan Resource Management

Basic Vulkan resource classes are implemented in context.cpp.

• The Context
• Command Buffers
• Linear Buffers
• Textures and Cubemaps
• Acceleration Structures

Geometries

There is abstract class called "Geometry". Each sub-class can have its own closest-hit shader and intersection shader (optional).

• ColoredUnitSphere: support a uniform color and different material types
• ColoredIndexedTriangleList: support a uniform color and different material types
• UnitSphereCheckerTex: procedure texture. diffuse only
• TexturedUnitSphere: 1 texture attached to 1 sphere. diffuse only
• TexturedTriangleList: support multiple textures. diffuse only
• WavefrontIndexedTriangleList: support multiple textures. support diffuse, specular, emissive material types. support alpha-map and bump-map.

Light sources

There are 3 Kinds of light-sources

• Emissive material: including the sky-box
• Sphere light sources
• Sunlight: round lights at infinite distance

PathTracer

The class "PathTracer" maintains a list of the geometries and path-traces them.

Next

As I've started FeiRaysInline, further exploration will happen there.