Tonemap Update and Code Reformatting

I haven’t done much in the way of large changes since last devlog but I have been reformatting much of my code to make it easier to read and use. The code should now look a lot cleaner. I also fixed the tonemapper as it was over over exposing the brighter spheres.

I also added a new tone map option that seems to be significantly better at representing bright colours than my prior two. The first one is purely clamping the HDR value to sRGB. As you may guess this leads to bright lights of most colours appearing white. I did have an alternative Reinhard tonemapper (v / (v + 1)) but that made everything look gray and desaturated as it applied the map to every colour channel individually causing all colours to look similar. The fix was to run the tone map with the brightest colour of the channel.

This new screenshot is done with the new tonemapper and is a great example of the new glass refraction. It is a bit dark sorry. This took >30min to render.

Java Path-Tracer

A simple Java Path-tracer for rendering cool scenes written in a single java class.

The main thing I have spent my time on is adding in a glass material. It has proved to be more of a pain than I originally thought. The book series Ray Tracing in One Weekend has once again proved very useful.

Anyway, whyle developing it I would repetitively get a material that looks somewhat like glass (or some weird blob) or something that was overly noisy. at one point my glass started emitting blue and yellow light (not much of a clue why that happened. After a good few hours of hassle I finally got it refracting properly. The rest of the features (total internal reflection & reflection) were fairly straightforward after that. Even caustics (the focused light under a glass sphere) work really well.

I also found that my metal bounce rays for fuzzie metals weren’t being normalised properly causing weird ring artefacts. That was an easy fix luckily.

I think this project is coming along well. Here is a new Hi-Res test scene that I let my laptop suffer on for quite a while. for reference this is an 8th gen i5 laptop and this scene took around 15 minutes to render. I did have a fair bit of other stuff open though. Enjoy. :)

Over the past few days i have made a few improvements. I have focused a bit more on the performance side of things and implemented (fairly bad) CPU multi threading as it was running single threaded before. This resulted in a 2-3x performance increase even though I went from 1 to 8 threads. I believe this is due to my bad code and the fact I create 8 new Thread objects every frame.

Other than performance optimisations I also expanded the functionality of the renderer. I added Lambertian scattering for more accurate matte surfaces. I gave metal a fuzziness propitiate that allows for more surface options. I also started to implement glass (which is an absolute pain) but it is still broken at the moment (see screenshots) :) I also did some general housekeeping and cleaned up the code making it easier to read.

The code is now visible on github for anyone who is interested.

This is my shot at making a (somewhat optimised) Path Tracer in Java. I have previously made one in scratch and am trying to make a better foundation to work off of so I can add more advanced features. I had already started making the ray traversal code but forgot to log it; my current time is a little on the low side. I primarily work of the online books ‘Ray Tracing In One Weekend’ as they contain most of the info I need. At the moment only spheres are supported and only can be matte or a light. Even now I have been able to make some cool renders of random spheres. I will soon add more surfaces (mirror, glass, etc), anti aliasing, and multi thread support for better performance. If I can I will add support for polygons and thus 3d models. I hope this is as cool to you as it is to me. Thanks for reading. :)

This project is my way to get familiar with Godot as it is my first time using the engine. I spent most of my time (after getting familiar with the engine) working with the shader script and tile maps (I made animated grass bc why not). Me and a friend have plans to recreate a game that I made is scratch a while ago and I am using this project to experiment with different assets and concepts of the game. I put a fair bit of effort into the magic shader for cast spells. It takes in a 3d noise map to display the coloured magic fog and also distorts the anything behind it. You can’t see it in the pictures but the magic is animated as the noise shifts along the Z axis making it swirl. So far I am enjoying Godot and hope to implement this into the full game when we make it. :) Here is the original game: https://scratch.mit.edu/projects/1204494990/