[esjeon]

I'm a bit puzzled here, after seeing the word "screen-space". I'm no game dev, but I know that there's tessellation shader for this very purpose. We can let the shader churn out more points on-demand in a separate step in the rendering pipeline. I think doing this in "screen-space" is a bit unnatural. (Just nitpicking.)

[teraflop]

"Screen space" refers to the coordinate system. Regardless of whether you were doing tessellation on the CPU or the GPU, you would want to use screen coordinates to make your decisions about which segments to subdivide, because what you care about is the deviation of the rendered curve from its "ideal" path. A large error in world coordinates doesn't matter if it's so far from the viewpoint that it looks tiny.

Tessellation shaders are useful for processing polygonal geometry with many thousands of polygons, but they have a fairly constrained programming model. And as you can see from the example images, rendering a high-quality orbit path only requires a few dozen vertices. The performance benefit from moving that computation into a tessellation shader is likely to be insignificant compared to the additional complexity and overhead.

[esjeon]

Thanks for the reply. I've written graphics code only on more-or-less lab environments, and have read many papers mentioning screen-space algorithms which trades off accuracy for other characteristics. Maybe I'm triggered by that. lol