How to make the Oil-leak effect

[polar1225]

Hi guys!i am working on a project about environmental protection.
I make the scene consist of seawater(addWaterSurfaceSceneNode()...) and a tanker.But how can i make the oil-leak effect like this.

And oil can be pieces of erased。。My idea is to use particle system。。but i really don't believe that can be authentic!

[CuteAlien]

Depends on how realistic you want it to be. You can get pretty good results with repeatable patterns. So in the center you have only "black" blocks. On the borders you have border-blocks with a few types of curves. That would be rather static, but depending on the type of game it would be sufficient. If you want it all dynamic - more tricky I guess ...

[polar1225]

Emm..The problem is to realize the spread of liquid effect..I have no idea!

[CuteAlien]

Your advantage is that most likely neither will your users have an idea how oil spreads realistically, so you probably get away with anything. Realistic distribution sounds hard. Fluid physics involving ocean waves, I guess you could probably do a doctoral thesis on that. So I only can give hints how games fake similar situations. Without having really dug deeper into this - my first approach to this would probably be to have a 2d-array covering the max-size I allow (before you lost the game anyway for example). The array would contain the amount of oil on each quadrant. And then there would be an update function which ones in a while goes over the whole array and depending on amount of oil in neighbor cells + some random factor it would increase the oil-value in fields (similar to the game life). And then display would use repeating patterns which just have to make sure they always have contact-lines with the neighbor fields. Speed of spreading oil etc ... just modify it until it plays well (if it is a game).

[ACE247]

A projected animated texture on the waves maybe? That would be simple and ideal, there's some source code for texture projection flying on the forum somewhere, search long enough and you'll find it, was part of a larger irrlicht glsl effects thing if im right.