OpenSceneGraph/examples/osgvolume/volume_tf_n_frag.cpp

108 lines
5.6 KiB
C++

char volume_tf_n_frag[] = "uniform sampler3D baseTexture;\n"
"uniform sampler3D normalMap;\n"
"uniform sampler1D tfTexture;\n"
"uniform float sampleDensity;\n"
"uniform float transparency;\n"
"uniform float alphaCutOff;\n"
"\n"
"varying vec4 cameraPos;\n"
"varying vec4 vertexPos;\n"
"varying mat4 texgen;\n"
"\n"
"void main(void)\n"
"{ \n"
" vec3 t0 = (texgen * vertexPos).xyz;\n"
" vec3 te = (texgen * cameraPos).xyz;\n"
"\n"
" vec3 eyeDirection = normalize(te-t0);\n"
"\n"
" if (te.x>=0.0 && te.x<=1.0 &&\n"
" te.y>=0.0 && te.y<=1.0 &&\n"
" te.z>=0.0 && te.z<=1.0)\n"
" {\n"
" // do nothing... te inside volume\n"
" }\n"
" else\n"
" {\n"
" if (te.x<0.0)\n"
" {\n"
" float r = -te.x / (t0.x-te.x);\n"
" te = te + (t0-te)*r;\n"
" }\n"
"\n"
" if (te.x>1.0)\n"
" {\n"
" float r = (1.0-te.x) / (t0.x-te.x);\n"
" te = te + (t0-te)*r;\n"
" }\n"
"\n"
" if (te.y<0.0)\n"
" {\n"
" float r = -te.y / (t0.y-te.y);\n"
" te = te + (t0-te)*r;\n"
" }\n"
"\n"
" if (te.y>1.0)\n"
" {\n"
" float r = (1.0-te.y) / (t0.y-te.y);\n"
" te = te + (t0-te)*r;\n"
" }\n"
"\n"
" if (te.z<0.0)\n"
" {\n"
" float r = -te.z / (t0.z-te.z);\n"
" te = te + (t0-te)*r;\n"
" }\n"
"\n"
" if (te.z>1.0)\n"
" {\n"
" float r = (1.0-te.z) / (t0.z-te.z);\n"
" te = te + (t0-te)*r;\n"
" }\n"
" }\n"
"\n"
" const float max_iteratrions = 2048.0;\n"
" float num_iterations = ceil(length(te-t0)/sampleDensity);\n"
" if (num_iterations<2.0) num_iterations = 2.0;\n"
" \n"
" if (num_iterations>max_iteratrions) \n"
" {\n"
" num_iterations = max_iteratrions;\n"
" }\n"
"\n"
" vec3 deltaTexCoord=(te-t0)/float(num_iterations-1.0);\n"
" vec3 texcoord = t0;\n"
"\n"
" vec4 fragColor = vec4(0.0, 0.0, 0.0, 0.0); \n"
" while(num_iterations>0.0)\n"
" {\n"
" vec4 normal = texture3D( normalMap, texcoord);\n"
" float v = normal.a; // texture3D( baseTexture, texcoord).s;\n"
" vec4 color = texture1D( tfTexture, v);\n"
"\n"
" normal.x = normal.x*2.0-1.0;\n"
" normal.y = normal.y*2.0-1.0;\n"
" normal.z = normal.z*2.0-1.0;\n"
" \n"
" float lightScale = 0.1 + max(dot(normal.xyz, eyeDirection), 0.0);\n"
" color.x *= lightScale;\n"
" color.y *= lightScale;\n"
" color.z *= lightScale;\n"
"\n"
" float r = normal[3]*transparency;\n"
" if (r>alphaCutOff)\n"
" {\n"
" fragColor.xyz = fragColor.xyz*(1.0-r)+color.xyz*r;\n"
" fragColor.w += r;\n"
" }\n"
" texcoord += deltaTexCoord; \n"
"\n"
" --num_iterations;\n"
" }\n"
"\n"
" if (fragColor.w>1.0) fragColor.w = 1.0; \n"
" if (fragColor.w==0.0) discard;\n"
" gl_FragColor = fragColor;\n"
"}\n"
"\n";