The "walking flames" bug

[mankrip]

My engine has a stupid bug, which also showed up from time to time in Makaqu: translucent static MDL entities starts slowly moving in a fixed direction. Sometimes their position is also affected by the camera position & angle, sometimes it's not.

The question is simple: how to make them stay quiet where they're supposed to be? What could be incrementing/decrementing their x/y position?
Their height always stays the same, by the way. It's only the x and/or y position that moves, which makes this bug even weirder.

I've made sure that the entity's ->origin, ->origin1 and ->origin2 are identical in CL_ParseStatic, and I'm also resetting the positional interpolation on every frame, so the positional interpolation isn't the cause.

[Spike]

svc_spawnstatic ents(eg flames) don't get reset every network frame unlike players etc, so make sure that anything you change while rendering gets unchanged after.
I assume you set a watchpoint (although tbh 'point' is a misnomer) to see when the ent's origin changes?

[mankrip]

I think the view itself may be changing for some reason. indicates that there's something going wrong in the frustum or whatever.

It may be related to my new method of depth-sorting liquid types. I was sure that nothing was modified during the sorting in my algorithm, but I'll have to check it again.

Despite everything in the software renderer being heavily intertwined, it's also a pain to track down. One of my goals is to untangle everything.