DRD Team

Additive Particles (spawned via a_custommissile) dissapear over 3D floors.
I discovered this when an imp through a fireball at me (the little twat) it was working fine with an additive flame then as soon as it goes over a 3D floor, only the 3D sphere I made is vissible, then it goes back to normal on leaving the 3D floor. Another example is when I was killing 3D Lost Souls over a 3D bridge, their fire stopped once they were over the bridge.

WAD, please. I don't know what limitation you run in here so I have to test it.

http://www.zshare.net/download/581036564be3df/
That link should download you a ParticleBug.pk3 file, ready to use straight away. The blue imp will throw a 3d ball with additive fire particles at you over a 3D floor, as soon as the projectile is in the 3d floor sector above the 3d floor, the additive fire disappears, then as soon as it leaves the sector, all goes back to normal.
You can also use "summon fire" to spawn the particle effect alone, if you do this whilst standing on the 3d floor, nothing apears.
I've tested this with nothing but the pk3, GZDoom 1.0.29 and doom2.wad. No sounds include (file size and irrelevant)

Your problem is simple: An object with zero dimensions can not be clipped properly because several calculations in the code assume that the height is positive. I fixed the specific cause for this one but you are still better off using a height of 1 instead of 0 to avoid other problems.

Good, seemed like a big problem then!