36 lines
1.7 KiB
Bash
36 lines
1.7 KiB
Bash
uniform mat4 uMVPMatrix; //总变换矩阵
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uniform mat4 uMMatrix; //变换矩阵
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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; //法向量
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varying vec3 vPosition; //用于传递给片元着色器的顶点位置
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varying vec4 vSpecular; //用于传递给片元着色器的镜面光最终强度
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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 specular, //镜面反射光分量
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in vec3 lightLocation, //光源位置
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in vec4 lightSpecular //镜面光强度
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){
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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 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; //最终的镜面光强度
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}
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void main() {
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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的位置
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vec4 specularTemp=vec4(0.0,0.0,0.0,0.0);
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pointLight(normalize(aNormal), specularTemp, uLightLocation, vec4(0.7,0.7,0.7,1.0));//计算镜面光
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vSpecular=specularTemp; //将最终镜面光强度传给片元着色器
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vPosition = aPosition; //将顶点的位置传给片元着色器
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}
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