So I've been zooming in ortho mode using the frusutm. That worked until the math involved leads to a problem when picking and being zoomed out a lot.
I was wondering if there are some viable alternatives.
What about scaling the whole scene according to the zoomlevels? How expensive is that operation?
i guess scaling the scene is cheaper than manipulating back and forth the frustum … since (as you experience) that just screws things up.
Yep, but manipulkating the frustum is the way that is suggested all over the net.
I am already transitioning my code to use scaling.