Rippling light through water effects

[Guessmyname]

I'm trying to make a light-rippling-through-water effect, where, well, light is going through water and being distorted, creating rippling highlights and shadows on the ground. It's a considerable problem to implement though, being basically animated light.

I suspect the best / possibly only real way of doing this would be using an animated texture with env_projected texture... does anyone know if this is even possible? The other problem being this would be very expensive to use.

If there are any other alternatives, that would also be grand. Animated cubemaps could work, but would require specialised mapping, textures and wouldn't really give you any shadows.

Potentially, animated additive decals could also be used in some cases, but only if, say, illuminating a wall or floor singularly, and nothing else. A bit like a cheaper version of the env_projectedtexture method above, but again - no shadows.

It's a tricky thing to try and do... any suggestions?

[tundra_cool]

I'm guessing you mean caustics. You could search for a simple texture online or make your own. Once you do, make a material file with the additive property and two texture scrolling proxies and make it so they scroll against each other. Then you have a choice. You could do something like use overlays and turn texturelock off to cover your underwater area but I'd personally export the piece of the map to .dxf and create a model which is 1 unit off of the map's geometry and UV it so the texture stretches at the side like real life. That'd be pretty cool. You now have me day-dreaming.

http://www.dgp.toronto.edu/people/stam/ ... stics.html

Perfect for textures.

[Major Banter]

Basically, wrong engine, unless you're going to code like a lunatic. I think I know where this is all going, and I'd love to see it work, but it'd be hideously complicated to do in Source. You've used all of my suggestions anyway

[TicTac]

Srred, I believe, did an effect like this a while ago. He used an animated texture, alpha blended to whatever he needed it 'cast' onto.

[surgeon]

there was a map in battlegrounds (the hl1 version) that had this effect in a cave. i think the rock texture was just animated with the static background and this effect overlayed on each frame.

[Major Banter]

Unless I'm mistaken, it means this:


Rather than this:


Otherwise it'd be a cheap overlay.

[TicTac]

Well, you can make the streaming effect with an animated volume-light model.

But I think he means cast thru a window onto walls/floors/etc, right?

[MayheM]

either one of those effects could be done with an animated texture. It would not be the easiest thing in the world to do, but I member a map back in CS 1.6 having that effect. For the life of me I can not remember the map name, but I do know it was done with animated textures or more accurately as tictac suggested with a model which uses said animated texture.

[Mess]

I'm pretty sure BMS has already implemented caustics with a simple animated texture

[Armageddon]

This might be cheap and I think it only works in tf2 but it still looks good. (Overlays on a water texture.)

http://www.youtube.com/watch?v=R8bGLLqpieA

[srredfire]

Srred, I believe, did an effect like this a while ago. He used an animated texture, alpha blended to whatever he needed it 'cast' onto.

Yupyup.

That the kind of effect you're looking for? ( on the back rock )

[Guessmyname]

Yeah, pretty much.

How can you make that sort of texture?

[Remonttimies]

I found this nice tool with google. It is a free program that is able to generate many different kind of animated water caustic effects.

I created this by myself: nice water effect

[TicTac]

I'm just gonna speak for Srred again He told me that he used an alphablend texture on the rock, but that would require you use displacements for everything you want this 'cast' onto. Best bet might be to make an animated overlay in various generic shapes (such as a small one for a window, or a large one for a skylight). If that doesn't work out, then jump into the mods code and enable a few more dynamic lights (projected textures) and use them sparingly.

[Guessmyname]

Yep. And for entirely underwater sections, there's always the LightmappedTwoTexture shader (animated caustic texture for $detail ftw!)