Shaders for use in a map..

[f-c-m]

Anyone have any experience with making shaders?
Just wondering how difficult it would be to make a shader with gradient transparency.. to be used to FAKE volumetric lighting in a map,

example : Street light, make a large cone brush emitting from the lightbulb of the streetlight that expands down onto the street below,
with a texture assigned to it, where the most opaque portion near the bulb, gradually going transparent as it reaches the street...
giving the illusion of volumetrics...

can this be done?
if so anyone have any ideas how it could be done?
I guess we only have Q3 shaders to relate to but i hear they are very similar

 

[Ti133700N]

Chaser also uses the same type of shaders, and yes I think it's possible (everything is possible in Source ) and not difficult, u make a gradient pic and you assing the opacity of the material through the texture, my guess

 

[Pi Mu Rho]

You can do that in HL already. Look at the tutorials on the Valve ERC.

 

[Papau]

You could do that with a cone mesh (brush would have visible edges), but it would only be on the surface of the cone. It would also have very high face count. I'm sure you know there are other ways to do this and this was just an example. Light isn't normally visible and most lighting is brighter at the source than at a distance.

I thought HL2 has volumetric (3d) textures. I know D3 does.

 

[f-c-m]

i wish..

I wish I knew if volumetric lighting existed with hl2,
because I really want to use that effect in my map
the places I would use this effect, the player wont be able to walk through the light, so the "outline" of the brush or mesh having that gradient transparency would work fine..
(im aware the insidebeyond the wall of the brush/mesh would not contain any texture etc..)...

im hoping this effect is not too difficult to achieve
if anyone has a URL to a tutorial that'd be great
havnt had any luck on the ERC.

 

[The Dark Elf]

Re: i wish..

Originally posted by f-c-m
I wish I knew if volumetric lighting existed with hl2,
because I really want to use that effect in my map
the places I would use this effect, the player wont be able to walk through the light, so the "outline" of the brush or mesh having that gradient transparency would work fine..
(im aware the insidebeyond the wall of the brush/mesh would not contain any texture etc..)...

im hoping this effect is not too difficult to achieve
if anyone has a URL to a tutorial that'd be great
havnt had any luck on the ERC.

ok can't remember if I said this before or not sorry lol, but check out spirit of half-life. One of the demo's included has a bit where you can shoot at a wooden wall, every bullet shot creates a kind of stream of light coming through it. Not exactly the kind of volumetrics your looking for, but it should have some handy advanced info on using/creating them.. By the sounds of it though you should be fine using the gradient idea with it and some additive rendering effect or something to get the effect your wanting. I think thats how its been done in HL1 before anyway

oh and blueshift has a large fan near the start with faked volumetric lighting which looks really neat (I always like the classic large fan in the ceiling with volumetric effects)