ZDoom

You're right! I didn't even realize my puff's height wasn't 1. Thanks a lot, that fixed it.

I imagine it has to do with the fact that [url=https://github.com/coelckers/gzdoom/blob/520d73edf61d890036f8ee592b5836d6b2a30345/src/g_shared/a_decals.cpp#L704]SprayDecal[/url] fires its linetrace from the center of the calling actor, meaning that if the puff's got the default BulletPuff height ( which itself is the default Actor height), then the decal would be offset upwards by 8mu. Potentially even more visually, due to differences in how the puff graphic and the decal graphic are offset.

Probably simple enough to fix by setting the puff's height to 1 or 2. 0 height [i]might[/i] not have any issues when given to something like a puff, but it kinda goes without saying that anything relating to collision being set to 0 will likely result in some dodgy nonsense.

I want to attach several decals to the puff for reasons. So the decal value is "none" and I use A_SprayDecal(varname) to spawn one of the possible decals. However, it spawns clearly too high.

[imgur]https://imgur.com/lc17LJy[/imgur]

Notice how the puff spawns below the crosshair position (which is normal with the default attackzoffset value) but the decal appears higher (in fact, at the height of the crosshair). The puff is a standard bulletpuff physics-wise.