【译】(Shader库),崎岖的球面环境正常映射
发表于2016-03-28
(Shader库),崎岖的球面环境正常映射
这里有一个新的入口（GLSL SHADER库）：一个崎岖球面环境的正常映射Shader（着色器）。一个GLSL Hacker的DEMO（译为，演示。后不翻译）已经可以使用，路径： moon3d/gl-320-bumpy-sphere-normal-mapping/ 的代码示例包的文件夹中。最新的GLSL Hacker可以在这里下载。就想这篇文章Shader一样，这个崎岖表面着色器，在片段着色器中计算空间中某方向的切线。
这里有GLSL顶点和片段着色器（支持OpenGL 3.2以上版本）
//*顶点着色器
#version 150
in vec4 gxl3d_Position;
in vec4 gxl3d_Normal;
out VertexData
{
vec4 Position;
vec4 OPosition;
vec4 Normal;
vec4 ONormal;
vec4 UV;
} vertex;
// GLSL Hacker automatic uniforms
uniform mat4 gxl3d_ModelViewProjectionMatrix;
uniform mat4 gxl3d_ModelViewMatrix;
void main()
{
vec4 P = gxl3d_ModelViewMatrix * gxl3d_Position;
vertex.OPosition = P;
gl_Position = gxl3d_ModelViewProjectionMatrix * gxl3d_Position;
vertex.UV = normalize(P);
vertex.Position = gxl3d_Position;
vertex.Normal = gxl3d_ModelViewMatrix * gxl3d_Normal;
vertex.ONormal = gxl3d_Normal;
}
*/
/*片段着色器
#version 150
in VertexData
{
vec4 Position;
vec4 OPosition;
vec4 Normal;
vec4 ONormal;
vec4 UV;
} vertex;
uniform sampler2D textureMap;
uniform sampler2D normalMap;
uniform vec3 color;
uniform float normalScale;
uniform float texScale;
uniform float useSSS;
uniform float useScreen;
float random(vec3 scale,float seed)
{return fract(sin(dot(gl_FragCoord.xyz+seed,scale))*43758.5453+seed);}
out vec4 FragColor;
void main()
{
vec3 vNormal = vertex.Normal.xyz;
vec3 vONormal = vertex.ONormal.xyz;
vec4 vPosition = vertex.Position;
vec4 vOPosition = vertex.OPosition;
vec3 vU = vertex.UV.xyz;
vec3 n = normalize( vONormal.xyz );
vec3 blend_weights = abs( n );
blend_weights = ( blend_weights - 0.2 ) * 7.;
blend_weights = max( blend_weights, 0. );
blend_weights /= (blend_weights.x + blend_weights.y + blend_weights.z);
vec2 coord1 = vPosition.yz * texScale;
vec2 coord2 = vPosition.zx * texScale;
vec2 coord3 = vPosition.xy * texScale;
vec3 bump1 = texture2D(normalMap, coord1).rgb;
vec3 bump2 = texture2D(normalMap, coord2).rgb;
vec3 bump3 = texture2D(normalMap, coord3).rgb;
vec3 blended_bump = bump1 * blend_weights.xxx +
bump2 * blend_weights.yyy +
bump3 * blend_weights.zzz;
vec3 tanX = vec3(vNormal.x, -vNormal.z, vNormal.y);
vec3 tanY = vec3(vNormal.z, vNormal.y, -vNormal.x);
vec3 tanZ = vec3(-vNormal.y, vNormal.x, vNormal.z);
vec3 blended_tangent = tanX * blend_weights.xxx +
tanY * blend_weights.yyy +
tanZ * blend_weights.zzz;
vec3 normalTex = blended_bump * 2.0 - 1.0;
normalTex.xy *= normalScale;
normalTex.y *= -1.;
normalTex = normalize( normalTex );
mat3 tsb = mat3( normalize( blended_tangent ),
normalize( cross( vNormal, blended_tangent ) ),
normalize( vNormal ) );
vec3 finalNormal = tsb * normalTex;
vec3 r = reflect( normalize( vU ), normalize( finalNormal ) );
float m = 2.0 * sqrt( r.x * r.x + r.y * r.y + ( r.z + 1.0 ) * ( r.z + 1.0 ) );
vec2 calculatedNormal = vec2( r.x / m + 0.5, r.y / m + 0.5 );
vec3 base = texture2D( textureMap, calculatedNormal ).rgb;
float rim = 1.75 * max( 0., abs( dot( normalize( vNormal ),
normalize( -vOPosition.xyz ) ) ) );
base += useSSS * color * ( 1. - .75 * rim );
base += ( 1. - useSSS ) * 10. * base * color * clamp( 1. - rim, 0., .15 );
if (useScreen == 1.)
{
base = vec3( 1. ) - ( vec3( 1. ) - base ) * ( vec3( 1. ) - base );
}
float nn = .05 * random( vec3( 1. ), length( gl_FragCoord ) );
base += vec3( nn );
FragColor = vec4( base.rgb, 1. );
}
*/
如果你需要这个区域球面环境正常映射Shader的话在这里
原文链接：http://www.geeks3d.com/20140521/shader-library-bumpy-sphere-env-normal-mapping/
版权声明：原文作者未做权利声明，视为共享知识产权进入公共领域，自动获得授权；