flickering lighting effect on 3d model (hud weapon)

[GelleSzebasztian]

tl;dr light flickers in LZDoom on the model, it doesn't in the most recent GZDoom, example pk3 provided.

Hello, I am new to this forum, I hope I am posting to the right place and the right way.

My 3d model weapon produces odd behaviour, when being lit by a dynamic light. The light flickers on the surface of it randomly, sometimes becomes entirely white for a moment. This thing does not happen in the recent versions of GZDoom, however it does in the recent versions of LZDoom (tested with few days old debuild and older version.) I didn't test it with older version of GZDoom, but since LZDoom is a fork of it, I suppose it would happen in those versions too.

It might be my fault, the model has unnecesarily big size, I admit it, with the tri-count of 7k, yet other models I have with similar complexity don't produce this behaviour. If I press escape, being in the menu, this happens more frequently, or if the weapon moves in some way. My drivers are up to date, I have 1080Ti
It also happens more often in full-screen maybe, but I am not sure. Is my model broken?

Unfortunately I can't provide screenshots, but I can provide a pk3 file
https://drive.google.com/open?id=1WEvfO ... 0JWl_tqtBy

Also I added a material to this model, because this way the glitch is more visible, and more annoying, however it keeps doing this without it too.

[drfrag]

It's a very old bug, it was already present in 3.51b1. I'll need to investigate it.

[drfrag]

Fixed, another not applicable patch.