Simple Raytracer

I did a lot of work this week, mainly working on implementing a UI similar to that of Blender’s with an outliner and properties panel for selecting and editing object data. I still have a few bugs to iron out, but I think it works pretty well! Next I want to fix some rendering issues with the BVH traversal code and also add more features like saving the scene, deleting and adding objects, plus other parameters for materials.

Did a lot of work behind the scenes, mainly updating the structure of the project. I’ve moved the different modules into their own folder now, so it is much easier to maintain.

A feature that I added a while back but couldn’t find much use for was textures, since you could only use one and it would affect all diffuse materials. With some work, I created a function that compresses the textures into an atlas to be passed to the GPU which then decodes it. After testing it out with some legacy Minecraft textures I found, I think it’s safe to say it looks pretty awesome!

I did a bit of work on various aspects of the raytracer. Most notably I redid a lot of the object loading code to use a new, more expandable system. Here is an example with a single cube (which would be broken up into 6 quads).

I made quite a few changes to the way the objects are processed before being sent to the GPU, mainly by removing a lot of the hard coding intended for sphere objects. Now I’m able to support other object types, notably this quad type that I’m showing off in this small Cornell Box scene. There’s a lot to be desired currently - the emissive materials aren’t bright enough, and this scene especially is very noisy. Overall however, I’m quite happy with the progress so far.

Added BVH construction to optimise the raytracer. It does speed up scenes with lots of objects by quite a bit, but I’m still not entirely happy with it, as it doesn’t perform quite as well as I had expected.

After moving onto the second book (Ray Tracing: The Next Week), I implemented texture loading into the GLSL shader. I also added depth of field, and cleaned up some of my previous work, like fixing the maths for the glass shader.

After quite some time, I’ve added a feature that I’ve wanted to add for a while: camera rotation! You can now use your mouse to look around the scene.

I finally added a way to adjust objects in the scene without having to change them from within the fragment shader; you can now create a .toml file and specify all the objects and materials in the scene.

Managed to get per-object materials to work, so you can have a metal shader on one object, and a diffuse shader on another! I also added a really cool glass shader, which surprisingly doesn’t tank performance that much.

Did some BTS work with updating the project structure and cleaned up some of the code. I also updated the github page and pushed the first v1.0 release.

I’ve finally added different materials to the raytracer! Currently you can choose between either Lambertian scatter (diffuse) or metallic scatter from within the fragment shader. In the future I’d like to make it easier to change parameters like materials and objects from the main loop, instead of the shader code.

Did some general chores, mainly cleaning up the shader preparation code by moving the loading functions to a helpers.c file. I also improved the denoising by making it more efficient and fixed frame blurring with movement (still a WIP as zooming isn’t fixed yet).

After lots of work, I finally got temporal denoising to work! Essentially, it accumulates each newly rendered frame by blending it with the previous one. I also fixed the previous hash seeding error.

First proper raytraced result!

I have a lot of work to do with updating the hash function to get rid of the striations and also optimise it, but this is a great result.

Next, I want to create a glossy material and try to make an emissive material (which isn’t part of the RTIOW blog)

:3

After lots of pain, I finally got the anti-aliasing code to work and added controls for it.

Getting closer to making the diffuse shader!

:3

Finished updating the fragment shader to use an abstraction for hittable objects, and added zoom and better movement functionality.

Next step is to add a diffuse shader for the first actual raytraced result!

Working on updating the fragment shader with an abstract struct for hittable objects.

Currently working on the code for the camera, with the help of the Ray Tracing in One Weekend blog.

Created the basic structure using Raylib. Implemented a simple fragment shader that displays the screen UV.