I recall reading somewhere, I think it was a Nexuiz based forum, that DP supports spotlights for RTlights. However, if you set up a spotlight in your map editor,
the normal light + info_null way, the rtlight is still an Omni directional light when in the engine. I've played with a bunch of the RTLight settings, but I seem unable to get the spotlight effect you would expect from doing it this way.
A search around the interwebs didn't really turn up much on this, so I'm looking really for anyone that's made spotlights work as RTLights.
From what I can gather, the *only* way to make a spotlight as an RTLight, is to put up with the engine making the spotlight RTlight as an omni-directional, but use a Cubemap attached to the light, drawn to resemble a spotlight. Although this method of creating cubemaps works, is there no easier / better option for making a spotlight?
I'm not fond of the idea of having to make a bunch of spotlight cubemaps, either in a "generic" form for use anywhere in levels, or specially created ones for specific lights. I also believe that using the cubemaps for spotlighting, wont give a very good realistic look, although the look might well be acceptable considering you dont often spend time admiring the visuals in Quake related projects.

My other query, DP doesn't seem to like "over-lapping" light/shadow area's, which makes sense for rendering speeds. Now, I'm not 100% sure how Quake4 actually does it, but in alot of the muliplayer maps, there quite often is alot of light's here and there, but only a couple appear to actually cast RT Shadows,
thinking this is a great optimization idea, I created a test map, simple 1 room job, 3 lights. ( 2 of the lights happened to be light+info_null spotlights, but meh, that didnt work properly anyway ), with 1 light being specifically set to cast shadows, the others having it turned off for their RTLights.
Now, so far all works as expected, you get one set of shadows cast from 1 light. But, how to make the light NOT cast light itself? Just Shadows?
The closest I could get was by setting the RTLight to have Ambient 0.0, Diffuse 0.1, Specular 0.0 and Color 0.2 0.2 0.2 with a radius of 9000.
This indeed gives me the shadow, but as you can probably already work out, the light is still giving out light, although very dim. ( The shadow is also quite dim, which isnt ideal for what I wanted, I was looking for a strong crisp dark shadow, but no light emission. )
So, does anyone know a way to make a light just cast shadows, with out any light emission, and are cubemaps really the only way to make spotlights using RTLights?
The reason I'm looking for such things, is my "complex" test map, based upon id's original Start map, could have alot more detail, and importantly, optimization if I could use proper spotlights and shadow casting only lights. Some screenshots of how it looks now:


Notice here how the window02_1 has semi-transparent glass, but a solid frame, showing the sky behind, and also using a cubemap kinda the same as how I forsee the useage of spotlights, casts the window02_1 image down as a light.


( Sorry to those that find the images 'too dark', but my project relies heavily on lighting and shadows for atmosphere, and the whole thing is very dark. )
EDIT:
Also, is there a way to use normal maps, specular maps on particles? Not tried it, but as an example, just adding particlefont_normal.tga, particlefont_gloss.tga to the particles folder? I'd like to ideally have particles that can be effected by lights, as certain alpha blended effects look horrid as fullbrights in dark area's. I'd also like to use the refraction shader which can be used on water/transparent stuff (like glass for example) in particle effects also, if anyone has an idea how to go about this.