GLSL Parallax Mapping

Graphics and GPU Programming Programming

Started by Enalis July 27, 2006 10:09 PM

18 comments, last by Vexator 17 years, 8 months ago

968

July 28, 2006 10:19 AM

Try the following for the height map sampling.

// use a scale of 0.05, try bias of 0 for nowfloat height = texture2D(heightMap, gl_TexCoord[0]).r - bias;float offset = scale * (2.0 * height - 1.0);vec2 newTexCoord = gl_TexCoord[0].st + viewVector.xy * height;

My shader does something to that affect.

Hope that helps

google

Enalis

333

Author

July 28, 2006 11:56 AM

Ok, so here's the change that I made:

// Get the height value and calculate the new texture coord.
float height = texture2D(heightMap, texCoord).r - bias;
float offset = scale * (2.0 * height - 1.0);
vec2 newTexCoord = texCoord.st + viewVector.xy * offset;

And what I did was as I lowered the size of scale it looked more like a normal texture. When I put it at 0.0001 it nearly looked like the original texture which makes sense because there's less offset. So here's my question, would it be possible that I have the wrong viewVector or something like that?

Douglas Eugene Reisinger II
Projects/Profile Site

Enalis

333

Author

July 28, 2006 12:07 PM

A few swift calculation changes and I'm almost there

float scale = 0.05float bias = 0.025float height = texture2D(heightMap, texCoord).r;//float offset = scale * (2.0 * height - 1.0);float offset = (height * scale) - bias;vec2 newTexCoord = texCoord.st + (viewVectorNew.xy * offset);

Here are the results
Almost Working...

Douglas Eugene Reisinger II
Projects/Profile Site

Vexator

138

July 28, 2006 12:42 PM

maybe you should take a look at the rendermonkey and shaderdesigner examples and look how they did it :)

Wunderwerk Engine is an OpenGL-based, shader-driven, cross-platform game engine. It is targeted at aspiring game designers who have been kept from realizing their ideas due to lacking programming skills.

blog.wunderwerk-engine.com

Eldritch

154

July 29, 2006 04:45 AM

I have made some parallax stuff too, but it looks kind of what the second screenshot shows, kind of messy and stretched. I used the code from the Shader Designer example. Though, I read someplace that I should use a heightmap that is bigger in size than the normal texture (i.e. texture = 256x256, heightmap = 512x512 instead of the other way around). Can this really be true?

Vexator

138

July 29, 2006 07:24 AM

i had the same problems with the shader designer sample as well, but i thought that it was simply my fault. their examples seem to be coded for a static camera only.. the intensity of the light was influenced by my camera movement, etc Oo

Eldritch

154

July 30, 2006 03:43 AM

Ah yes, that is correct... Shader Designer uses a static camera.. hmm, so how did you solve it? Should only be a small revamp of some portion of the code I guess :)

Elvis Enmanuel

142

July 30, 2006 04:09 AM

Are u sure that the camera an light uses right coordinates when you send to the shader? With my TBN matrix I need to negate the tangent vector.

ains

Eldritch

154

July 30, 2006 07:22 AM

I am not even sure I am calculating the tangents and binormals correctly :)

Vexator

138

July 30, 2006 12:08 PM

http://www.terathon.com/code/tangent.php

works fine, using it in my engine, too.

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