Help questions about rendering ellipsoids

[josemendez]

Hi !


I was trying to write my own shader for fluid rendering these days. I've read the  codes for ellipsoid rendering in ObiEllipsoids.cginc and I've come across some questions about the visible ellipsoid radius in "VisibleEllipsoidCircleRadius" and "IntersectEllipsoid". Why is the radius equals to sqrt(1-t) ? And according to the fragment shader in FluidThickness.shader,  the mapping.w is  the visible ellipsoid radius,  but when doing the intersection detection in function "IntersectEllipsoid" on line "float iq = 1 - r2/mapping.w", why do we use mapping.w instead of square of mapping.w ? Perhaps I've misunderstood  about  the ellipsoid radius, is there any reference or article about this part for further reading?

Thanks!

Hi there!

Obi implements this article:
https://tu-dresden.de/ing/informatik/smt...df?lang=de

There the math is laid out in a very detailed way. Let me know if I can be of further help!