The Space Jump effect is pretty simple when looking at its individual components.

Previously I created a 3D star field for the environmental rendering.

I use the 3D locations of these stars in the effect.

When the effect starts, I start cranking up the light emitted for each star.

This is done by just …

In 3D, 1+1 vector doesn't necessarily make it a 2 vector. That only works correctly if both vectors are fully aligned. Ie (1, 0, 0) + (-1, 0, 0) is much shorter than length 2.