Jump to content
  • Advertisement
Sign in to follow this  
Chris Weaver

Parallax and environment mapping woes

This topic is 3733 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi, I'm trying to do parallax bump mapping and environment mapping but there seems to be something wrong with the transformations or vectors in my shaders. I'm fairly sure the tangent space vectors and the world transform sent to the shaders are correct, but when using the following code I get two problems: a. The parallax effect is not 3d and is 'swimming' over the surface with different viewing angles. b. The reflections are all incorrect and distort/stretch off to infinity at shallow viewing angles. Can anyone see what I maybe doing wrong? Vertex Shader #version 120 attribute vec3 Normal; // Object space normal attribute vec3 Tangent; // Object space tangent attribute vec3 Binormal; // Object space binormal attribute vec3 BumpMultiTexCoord; // Using instead of gl_MultiTexCoord1 uniform mat4 View2World; // View space to world matrix varying vec3 view; varying vec3 normal; varying mat3 tbnWorldMatrix; // Tangent to world space matrix varying vec2 bumpTexCoord; void main(void) { gl_TexCoord[0] = gl_MultiTexCoord0; // Base Texture coords gl_Position = ftransform(); bumpTexCoord.xy = BumpMultiTexCoord.xy; // Bump map coords // Calculate view to tangent space matrix vec3 t = normalize(gl_NormalMatrix * Tangent);// Tangent object -> view space vec3 b = normalize(gl_NormalMatrix * Binormal); // Binormal object -> view vec3 n = normalize(gl_NormalMatrix * Normal); // Normal object -> view space mat3 tbnMatrix = mat3(t, b, n); // Calculate tangent space normal normal = normalize(gl_NormalMatrix * Normal); // View space normal normal = normalize(normal) * tbnMatrix; // Calculate view space view vector vec4 vert = gl_ModelViewMatrix * gl_Vertex; vec3 viewVec = vec3(-vert); // Calculate tangent space view vector // ** Reflections work better without the normalize here for some reason? ** view = normalize(viewVec) * tbnMatrix; // Calculate tangent to world matrix tbnWorldMatrix = transpose(tbnMatrix) * mat3(Cam2World); } Fragment Shader #version 120 uniform sampler2D BaseTexture; uniform samplerCube CubeMap; uniform sampler2D BumpMap; uniform mat4 View2World; varying vec4 col; varying vec3 view; varying vec3 normal; varying mat3 tbnWorldMatrix; varying vec2 bumpTexCoord; void main(void) { vec2 cBumpSize; cBumpSize.x = 0.04200002; cBumpSize.y = -0.0299999; // Find parallax offset float height = texture2D(BumpMap, bumpTexCoord.xy).a; height = height * cBumpSize.x + cBumpSize.y; vec3 viewVec = normalize(view); vec2 newBaseUV = gl_TexCoord[0].xy + viewVec.xy * height; // View vector in tangent space for fragment vec3 V = normalize(view); // Calculate reflection vector of view vector around normal vec3 N = normalize(normal); vec3 R = reflect(V, N); // Transform reflected vector back into world space R = tbnWorldMatrix * normalize(R); // Look up into the env_map after transforming into world coordinates gl_FragColor.rgb = textureCube(CubeMap, R).rgb; // Apply parallax mapping // gl_FragColor.rgb = texture2D(BaseTexture, newBaseUV).rgb; gl_FragColor.a = 1.0; } Some of this code is from the Shader Designer examples, but I seem to be doing something wrong. Thanks in advance, Chris.

Share this post

Link to post
Share on other sites
Sign in to follow this  

  • Advertisement

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

Participate in the game development conversation and more when you create an account on GameDev.net!

Sign me up!