59 lines
2.4 KiB
Bash
59 lines
2.4 KiB
Bash
uniform int isShadow;//阴影绘制标志
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uniform mat4 uMVPMatrix; //总变换矩阵
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uniform mat4 uMMatrix; //变换矩阵
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uniform mat4 uMProjCameraMatrix; //投影、摄像机组合矩阵
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uniform vec3 uLightLocation; //光源位置
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uniform vec3 uCamera; //摄像机位置
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attribute vec3 aPosition; //顶点位置
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attribute vec3 aNormal; //顶点法向量
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varying vec4 ambient;
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varying vec4 diffuse;
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varying vec4 specular;
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//定位光光照计算的方法
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void pointLight( //定位光光照计算的方法
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in vec3 normal, //法向量
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inout vec4 ambient, //环境光最终强度
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inout vec4 diffuse, //散射光最终强度
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inout vec4 specular, //镜面光最终强度
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in vec3 lightLocation, //光源位置
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in vec4 lightAmbient, //环境光强度
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in vec4 lightDiffuse, //散射光强度
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in vec4 lightSpecular //镜面光强度
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){
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ambient=lightAmbient; //直接得出环境光的最终强度
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vec3 normalTarget=aPosition+normal; //计算变换后的法向量
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vec3 newNormal=(uMMatrix*vec4(normalTarget,1)).xyz-(uMMatrix*vec4(aPosition,1)).xyz;
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newNormal=normalize(newNormal); //对法向量规格化
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//计算从表面点到摄像机的向量
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vec3 eye= normalize(uCamera-(uMMatrix*vec4(aPosition,1)).xyz);
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//计算从表面点到光源位置的向量vp
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vec3 vp= normalize(lightLocation-(uMMatrix*vec4(aPosition,1)).xyz);
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vp=normalize(vp);//格式化vp
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vec3 halfVector=normalize(vp+eye); //求视线与光线的半向量
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float shininess=50.0; //粗糙度，越小越光滑
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float nDotViewPosition=max(0.0,dot(newNormal,vp)); //求法向量与vp的点积与0的最大值
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diffuse=lightDiffuse*nDotViewPosition; //计算散射光的最终强度
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float nDotViewHalfVector=dot(newNormal,halfVector); //法线与半向量的点积
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float powerFactor=max(0.0,pow(nDotViewHalfVector,shininess)); //镜面反射光强度因子
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specular=lightSpecular*powerFactor; //计算镜面光的最终强度
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}
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void main()
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{
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if(isShadow==1)
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{//绘制本影，计算阴影顶点位置
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vec3 A=vec3(0.0,0.1,0.0);//投影平面上任一点坐标
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vec3 n=vec3(0.0,1.0,0.0);//投影平面法向量
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vec3 S=uLightLocation; //光源位置
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vec3 V=(uMMatrix*vec4(aPosition,1)).xyz; //经过平移和旋转变换后的点的坐标
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vec3 VL=S+(V-S)*(dot(n,(A-S))/dot(n,(V-S)));//求得的投影点坐标
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gl_Position = uMProjCameraMatrix*vec4(VL,1); //根据总变换矩阵计算此次绘制此顶点位置
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}
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else
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{
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gl_Position = uMVPMatrix * vec4(aPosition,1); //根据总变换矩阵计算此次绘制此顶点位置
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}
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pointLight(normalize(aNormal),ambient,diffuse,specular,uLightLocation,vec4(0.4,0.4,0.4,1.0),vec4(0.7,0.7,0.7,1.0),vec4(0.3,0.3,0.3,1.0));
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} |