llbit

Today I implemented some improvements to the Render Controls dialog. I added text fields where the user can input specific values for dof (depth of field), fov (field of view) and focal offset. Setting dof to the maximum value now causes infinite depth of field (everything is in focus). I also added a status field in the dialog that shows some info for the current frame.

I’ve also been testing OpenCL. I wrote a test program that basically just ray traces a sphere. OpenCL is pretty fun to play with so far, but I doubt I’ll have the patience to add full OpenCL support in Chunky.

The Minecraft ray tracing and path tracing work I’ve been doing lately is all still very experimental/unstable and lacks a good GUI.

For instance, today I added some controls to let the user adjust the depth of field effect, but it’s nowhere near as usable as it should be. It’s kind of tricky finding the correct focal offset to make the render look just the way you want it. Making GUI stuff like this work seamlessly becomes more difficult the larger the program gets.

I’m kind of afraid of releasing the path tracing stuff and then getting swamped by bug reports and feature requests. I’ll release it to the general public eventually (Open Source of course, just like the rest of Chunky), but it needs more polish. I’m thinking of doing a closed alpha until then.

I tossed out all my physical lens simulation work, and decided to use a quick and dirty depth of field technique instead. It’s not a physically correct lens simulation, but it gets the job done and it’s a lot cheaper computationally which is a big plus. The depth of field effect really helps create a better sense of distance in the rendered images. Now I just need to add some means of controlling the aperture and focal length.

An example of depth of field effects. Notice that near and far objects are blurred.

I think the best bet for simulating a camera lens in my path tracer will be to use some form of thin lens approximation. So far I’ve managed to create some extreme telephoto lenses that produce pretty cool images:

I was experimenting with different lens transformations today, with the goal of simulating depth of field. It sort of works, just not as intended.