8 replies to this topic

[Reedbeta]

I didn't think these were worth submitting to dev-snapshot, as they're not really that great. Progress is slow since I'm a college student who only has time to work on graphics when he's not doing homework =) Clicky to open bigger versions.

Parallax and diffuse/specular bump mapping:

Reflection with a dynamic cubemap and Fresnel shader:

Reflection/refraction:


These were developed in OpenGL and the shaders are written in GLSL. Yeah I know the scene's not that interesting - a square room and a table, but the point of these things was to develop the shaders, not make a really kick-ass looking scene. That's next on my list, after shadow mapping =)

[Dia]

Very nice work. Parallax bump mapping is very interesting. It is interesting to see how just two extra lines in the shader produces such a cool-looking effect.

From certain views, it looks almost the same as real displacement mapping.

[Ed Mack]

How is paralllax bump mapping done?

[Reedbeta]

It's a cheap substitute for displacement mapping, using a height map to slightly offset the texture coordinates so that it appears the surface has depth, by simulating the 'parallax' effect that happens when you move past a surface (the parts closer to you appear to move at a faster rate than the farther parts). It's a very simple and cheap effect but it provides a powerful visual cue, especially when combined with bump mapping. However the illusion is broken if you look at the surface from a direction far from the normal. It also tends to look odd where two surfaces join together, like at the corner of the walls in the first shot, or where the table legs meet the floor.

For more info: http://www.infiscape...lax_mapping.pdf

[Ed Mack]

Thanks! That's quite cool. (My google for 'parallex mapping' didn't get many results for an obvious reason :))

[bladder]

have you guys seen this before?

You can see a video of relief mapping here:

http://www.shadertech.com/contest/

[Reedbeta]

I hadn't seen that. That looks like a really awesome effect - unfortunately, it doesn't run on my Radeon 9600 =(

[bladder]

yeah, it's a pretty intesive effect. The video was using the nv40 pipeline. I think the 6800 is the only card that can handle that effect at this time. And even with that it's not very efficient for real time. Get a whole level of relief mapped data and it should theoretically bring your processor to its knees.

Maybe some form of relief lod will be used. But for now, I guess parallax mapping is going to become the standard bump mapping technique.

I remember reading (dont remember where) that someone got parallax mapping working in doom 3? Anyone else heard of that?

[Dia]

Yeah, there's a mod for doom3 that makes the bump maps use parallax mapping. Here's the link: http://www.nerdinside.net/~junkguy/

He also implemented cell shading, giving doom a cartoonish look while playing.