> GPUs ... basically only know how to rasterise triangles.
www.shadertoy.com would like a word.
Re:Sphere Rendering
by azornathogron on Wednesday June 05, 2024 @06:41PM
(#40591476)
Pixel shaders are covered in parts 8 and 9 of the blog series I linked to.
What aspect of shadertoy disagrees with what I wrote?
All of it that shows rendering beyond what GPUs "only know".
Re:Sphere Rendering
by azornathogron on Thursday June 06, 2024 @02:40AM
(#40594266)
I said "rasterisation", not "rendering".
Rasterisation is one specific step of the rendering process (+). GPUs rasterise triangles. If you're writing a software renderer you can include algorithms to directly rasterise other shapes such as circles, which is what started this whole thread. But if you're rendering with a GPU and relying on its built in rasterisation then triangles is where you start, even if circles is what you ultimately want.
(+) It's also possible to render without the rasterisation step at all - for example, a pure ray tracing based renderer doesn't have an explicit rasterisation step as it's normally thought of in graphics terms.
This is a great series of blog posts about how GPU based rendering is structured (long but excellent if you're interested):
https://fgiesen.wordpress.com/2011/07/09/a-trip-through-the-...
Part 6 is about rasterisation.