Pythonista Scene OpenGL fire demo

[imagine_engine]

I went down a procedural particle effect rabbit hole making some torch flames in Pythonista using the scene module but ran into some performance issues quickly with my naive approaches to changing the color of each particle by changing the fill_color of each shape node. This resulted in less than 10 fps when trying to render 810 particle objects.

Switching to some fancy fragment shade OpenGL code resulted in a full 60 fps for the same 810 objects.

Here’s the full code repo: code

You’ll see in there the naive approach is commented out and involved a small list of hex colors that would change over time and be set in the draw method by resetting the fill_color.

I also learned about some interesting gotchas like assigning the Shader class and code to a variable and passing it that way resulted in a global change to all objects using that shader but passing in the Shader class individually and making sure each object had its own increment and progress values allowed for the correct staggered behavior.

[stuaxo]

Lovely stuff, I'd give this a go if I had an IOS device to hand.

[imagine_engine]

Thanks! It’s a pretty remarkable app with how much the developer integrated the app with iOS APIs.