Water foam effect

[maximsubbota]

Hi, I need help in design for my level.
I have a river and I want to create an effect that makes foam in the texture wen the water collides with a mesh like in this photo around the submarine.
http://img195.imageshack.us/img195/6842/sh5subsim4.jpg

or here, in this video. http://www.youtube.com/watch?v=zObKrJY0Nnk

any ideas?

thanks to all, and sorry for my english.

[brunomartelli]

that looks great, use some sort of particle system, look at the UDK examples

[maximsubbota]

But it Will be very expensive to use particle systems along the all river, I want to create an effect lije in just cause 2

[jonm4y]

sorry ive got nothing to add of any help here. just wanted to say that image looks amazing! good work man!!

[Adrenen]

Most likely it is not his work , as you can see there is foam effect which he asks about
It would work best as some animated decals , would need coding though to put it together ( no idea how )

[Max Power]

You could use DepthBiasedAlpha to Lerp between an ocean and seafoam appearance upon contacting objects.

[Snipe34]

Hamad's tut came from a UDK forums link, but his studio link is all I wrote inside my resultant ocean material:
http://www.alhasanstudio.com/?page_id=61

Presuming you probably don't have some water...

Wish I knew more details of what max was talking about, sigh.

For the sub there's vehicle attachments like dust for land and that would probably work for a sub water effect attachment, so that's probably what you'll be wanting to modify.

brunomartelli mentions particles - a few splashes of particle spray in obvious places would be helpful, so not too cpu intensive.