>>725279520
You're asking for two things that cannot exist at the same time. If you want them to be orderly you could choose a population plane for either all triangles or all groups of connected triangles. But you will never get them to land on the outlines or arbitrary triangles this way since you'll be colouring in the dots at all points that are inside so you get jaggies. Additionally even if you tried to draw dots on the outline, and the dots were similarly spaced, for two triangles next to each other you might get issues of drawing twice on the common edge.

Don't know the wider context but you could do the choosing of the common plane based on the first triangle you start with but that wouldn't work if the triangle order can change between frames so you'd flicker between different patterns. If this is for something like colouring in selected area on the ground for a top down, might be best to choose something like the ground plane. If it's to make a halftone type filter just use perpendicular to camera