Introduction to Cycles Internals

Have you ever wondered what a BVH is?
Have you ever wondered what a BSDF is and why you can't connect it to a color input?
Have you ever wondered why adding a single emissive triangle to a scene that was lit by lamps doubles your noise?
Have you ever wondered what MIS is and why it appears in four seemingly unrelated places?
Have you ever wondered why motion blur on hair takes forever to render?
Have you ever wondered why glass windows make your interior noisy?
Have you ever wondered why Cycles is so much slower than Eevee?
Or have you ever simply wondered what your computer actually *does* when you press F12?

Then this talk is for you!
In it, I'll explain the basics of what Cycles does, how it does it and why it doesn't (yet!) do some things as well as you'd like it to.

No math or code will be involved and no previous knowledge of path tracing is assumed, so the talk is not just for existing developers but for all existing and future users of Cycles.


  • I'm a software developer working on Cycles for the last eight years, developing features such as the original denoiser or light portals as well as a lot of internal improvements and speedups.

    Over the years I've worked with various studios such as Theory Studios and Tangent Animation on improving Blender for their projects, and now I'm working on Cycles through a Development Fund grant.


    read more.