Parallel lines in 3D space

[glv]

Hello @paulstgeorge,

Thanks for this topic! Refreshing my math and Processing helps visualize concepts… especially cross and dot products.

I gleaned some concepts to create local planes from:

Points on the surface of a Sphere using beginShape(POINTS or QUADS)

I’m happy now! I use the cross product to calculate a local coordinate space perpendicular to the sphere. I add all vertices in setup() to a PShape and only call shape(dots) to draw them all at once in draw(). I hope it is useful for others. Best wishes, Rick [cross] float dotRadius = 4; float sphereRadius = 250; PShape dots; void setup() { size(700, 700, P3D); dots = createShape(GROUP); for (int i=0; i<1000; i++) { PVector n = PVector.random3D().mult(sphereRadiu…

And was able to create infinite parallel lines:

Other resources I found useful:

3D Rotations in Processing (Vectors, Matrices, Quaternions)

How to find perpendicular vector to another vector?

Can you draw a quick 2D sketch (paper or Processing) to illustrate what you are trying to achieve?

:)