I found an alternative to calcplot3d. It's called Graphing Calculator 3D , and there's a freebie version that works pretty well for toratopes and genus-0 surfaces from my STEMP notation (cube, triangle prism, sq pyramid, etc).
So, finally! A standalone, offline program that rivals calcplot3d. Features adjustable resolution, color mapping, wireframe, shinyness, night mode, among a few others. Only drawback is two adjustable parameters only. No big deal at all. The graphs look nice, and it renders fast (for a 5d toratope, as tested so far).
You can also save files to upload and share.
Check it out:
Graphing Calculator 3D