79 lines
2.1 KiB
GLSL
79 lines
2.1 KiB
GLSL
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// osgOcean uniforms
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// -------------------
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uniform float osgOcean_WaterHeight;
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uniform vec3 osgOcean_Eye;
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uniform vec3 osgOcean_UnderwaterAttenuation;
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uniform vec4 osgOcean_UnderwaterDiffuse;
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uniform bool osgOcean_EnableUnderwaterScattering;
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// ------------------
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uniform vec2 uHeightRange;
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uniform float uOneOverHeight;
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uniform mat4 osg_ViewMatrixInverse;
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varying float vUnitHeight;
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varying vec3 vLightDir;
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varying vec3 vEyeVec;
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varying vec3 vExtinction;
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varying vec3 vInScattering;
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varying vec4 vWorldVertex;
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attribute vec3 aTangent;
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void computeScattering( in vec3 eye, in vec3 worldVertex, out vec3 extinction, out vec3 inScattering )
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{
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float viewDist = length(eye-worldVertex);
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float depth = max(osgOcean_WaterHeight-worldVertex.z, 0.0);
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extinction = exp(-osgOcean_UnderwaterAttenuation*viewDist*2.0);
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// Need to compute accurate kd constant.
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// const vec3 kd = vec3(0.001, 0.001, 0.001);
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inScattering = osgOcean_UnderwaterDiffuse.rgb * (1.0-extinction*exp(-depth*vec3(0.001)));
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}
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void main(void)
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{
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gl_TexCoord[0] = gl_MultiTexCoord0*vec4(16.0,16.0,1.0,1.0);
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gl_TexCoord[1] = gl_MultiTexCoord0*vec4(20.0,20.0,1.0,1.0);
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gl_TexCoord[2] = gl_MultiTexCoord0*vec4(25.0,25.0,1.0,1.0);
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vec3 vertex = vec3(gl_ModelViewMatrix * gl_Vertex);
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vEyeVec = -vertex;
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vec3 n = normalize(gl_NormalMatrix * gl_Normal);
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vec3 t = normalize(gl_NormalMatrix * aTangent);
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vec3 b = cross(n, t);
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vec3 tmpVec = vec3(gl_LightSource[0].position.xyz);
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tmpVec = normalize(tmpVec);
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vLightDir.x = dot(tmpVec, t);
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vLightDir.y = dot(tmpVec, b);
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vLightDir.z = dot(tmpVec, n);
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tmpVec = -vertex;
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vEyeVec.x = dot(tmpVec, t);
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vEyeVec.y = dot(tmpVec, b);
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vEyeVec.z = dot(tmpVec, n);
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gl_Position = ftransform();
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gl_ClipVertex = gl_ModelViewMatrix * gl_Vertex;
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gl_FogFragCoord = gl_Position.z;
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float inv = 1.0 / ( uHeightRange.y - (uHeightRange.x+65.0) );
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vUnitHeight = inv * (gl_Vertex.z - (uHeightRange.x+65.0));
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vWorldVertex = (osg_ViewMatrixInverse*gl_ModelViewMatrix) * gl_Vertex;
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if( osgOcean_EnableUnderwaterScattering )
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{
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computeScattering( osgOcean_Eye, vWorldVertex.xyz, vExtinction, vInScattering );
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}
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gl_Position = ftransform();
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}
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