View Full Version : How do you fake an ocean in RT?

04-22-2007, 01:16 PM
How do you create an ocean without procedurals, just with image maps and maybe incidence angle fresnel effects?
What images do you use (or how do you generate them)?
How do you hide the horizon? Do you apply the displacement map everywhere (upto the horizon)?
How do you prevent tiling of the textures? Do you write your own shaders? If so, what do they do?

Many questions :)
Thanks alot, if you need to know more to help me, just ask :)


04-23-2007, 03:26 AM
i can answer some.(not all,too high wish for current RT)

basically bump-mapping or normal-mapping is best and easy way i guess.

What images do you use (or how do you generate

just "clouds" image of photoshop.
it very easy and good result.
see my sample program below.


its japanese but u can find #166. its ocean shader sample.
and it sample use height map .that height map is photoshop clouds image i made with photoshop ->render->clouds.it took only 1 min or less.

How do you hide the horizon? Do you apply the displacement map everywhere (upto the horizon)?

displacement map is not available most of cards.
nvidia offisialy annouced they no longer support displacement mapping some years ago.
for hiding horizon,if me,just put fog.

fog sample is #209 and #210.

04-23-2007, 08:20 AM
Thanks Katsh! I used google to translate it. Much information at your place :)
Some more questions: What's the difference between a height map and a displacement map? It's not the same? I just need a map that will deform the geometry of the surface; has a heightmap that function?

Regarding the specifications, the engine is openGL based (PIM) and can all sorts of stuff. The engine won't limit me, I just have to figure out how to achieve everything.


04-23-2007, 08:43 AM
I use a normal map, layered twice, one mapped bigger and moving faster (though in the same direction), with a colour map moving on top of that. A fresnel effect controlling the specular and possibly reflection of a cubic reflection map.

04-23-2007, 09:09 AM
height map is just simple map-image.u know when u start LW in order to acheave bump-mapping ,u must be made somwe sort of map-image that consist of black and white.thats the height map.not complex.

"map"(image) can be same.
defference is USAGE of the images.
so, u can use same map-image for bump-mapping or disp-mapping.
each mappipng just need information of something contrasting density. anyway its 1D information. so simple.

as u said,displacement-mapping is the technique that will deform the geometry.
but bump-mapping and normal-mapping is just a cheap trick,that will not deform the geometry.

oh it didnt need thinking vid card limitation for u,sorry.
yea openGL is more multifunctional. i bet it can all u want. especially ur enviromet :P

well, ne1 knows Direct3D10 or newest information about displacement map.
or anything?

04-23-2007, 09:45 AM
Thanks to both of you. I'll try it with normal, color and displacement (height) maps. Hehe, I just found the developers page at nvidia. There's cool stuff, I think I'll test their normal map baker.