Yeah, but that's at an "i wish" position right now. No one in the q3 engine scene has implemented such thing yet nor is interested to do it with the old fashioned ARB method
One engine is doing it through GLSL (XreaL) but it's got so much other effects that's not needed (per-pixel shadows) and has a very slow speed, and oh it's not compatible with the same gamecode and relies on other non-free things.
I did ask about this once in a q3 engine forum but they told me to switch to a buggy,
QUAKE2 derived engine QFusionFX or a proprietary non-free engine called mE++. Hell with that!