Antialiasing

[notEvil]

Hi,

I did some surface and line plots recently and found the amount of aliasing rather distracting. Then I discovered SMAA and SSAA postprocessing in three.js and tried to add them to the plots. After a lot of trial and error (I'm not really familiar with js/ts and dev workflow) I was lucky and got:

(from left to right: master branch, master + smaa, master + ssaa)

There is WebGLRenderer(...antialias=true...) but never saw any antialiasing applied. Are plots supposed to be antialiased? If not, optional SSAA would be a very nice feature.

Misc:

• I had to modify three.js/postprocessing/SSAARenderPass to render multiple scenes to make it work, and ignored large parts like volume rendering and resize events, so its a rather hacky solution
• the plot looks the same in Firefox, Chrome and Linux, Windows

[notEvil]

part2 Out of curiosity I tried to figure out how SSAA would work for volume rendering and didn't find a simple solution. Then I noticed WebGLMultisampleRenderTarget which was introduced to threejs in r101. Again, dodging the obstacles as they appeared I managed to bump threejs to r137 and got a nicely multisampled output.

r101 didn't work because of a stencil format issue which was fixed in r106. r106 didn't work because for some reason rendering to the multisampled target would force clear. So I decided to try r137 and there the issue has been resolved. The necessary adjustments to ipyvolume were minor, just one obstacle remained: pythreejs deserializes the ShaderMaterial objects without three.ShaderMaterial as prototype. I "fixed" it by using Object.setPrototypeOf just before the exception (before material.onBeforeRender in three.module.js:~27080). Obviously volume rendering is still broken, but maybe the remaining issues are easier to solve.

Long story short: I believe ipyvolume would benefit from a more recent version of threejs. Afaik the main obstacle is pythreejs which isn't going to support newer releases of threejs anytime soon (https://github.com/jupyter-widgets/pythreejs/issues/359).

Anyways, it was a fun experience and maybe someday its actually useful. If anyone is interested, I will fork and push the changes.