2022-09-19 18:05:01 +08:00

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uniform mat4 uMVPMatrix; //总变换矩阵
uniform mat4 uMMatrix; //变换矩阵
uniform vec3 uLightLocation; //光源位置
uniform vec3 uCamera; //摄像机位置
attribute vec3 aPosition; //顶点位置
attribute vec3 aNormal; //顶点法向量
//用于传递给片元着色器的变量
varying vec4 vambient;
varying vec4 vdiffuse;
varying vec4 vspecular;
void pointLight( //定位光光照计算的方法
in vec3 normal, //法向量
inout vec4 vambient, //环境光最终强度
inout vec4 vdiffuse, //散射光最终强度
inout vec4 vspecular, //镜面光最终强度
in vec3 ulightLocation, //光源位置
in vec4 lightAmbient, //环境光强度
in vec4 lightDiffuse, //散射光强度
in vec4 lightSpecular //镜面光强度
){
vambient=lightAmbient; //直接得出环境光的最终强度
vec3 normalTarget=aPosition+normal; //计算变换后的法向量
vec3 newNormal=(uMMatrix*vec4(normalTarget,1)).xyz-(uMMatrix*vec4(aPosition,1)).xyz;
newNormal=normalize(newNormal); //对法向量规格化
//计算从表面点到摄像机的向量
vec3 eye= normalize(uCamera-(uMMatrix*vec4(aPosition,1)).xyz);
//计算从表面点到光源位置的向量vp
vec3 vp= normalize(ulightLocation-(uMMatrix*vec4(aPosition,1)).xyz);
vp=normalize(vp);//格式化vp
vec3 halfVector=normalize(vp+eye); //求视线与光线的半向量
float shininess=50.0; //粗糙度,越小越光滑
float nDotViewPosition=max(0.0,dot(newNormal,vp)); //求法向量与vp的点积与0的最大值
vdiffuse=lightDiffuse*nDotViewPosition; //计算散射光的最终强度
float nDotViewHalfVector=dot(newNormal,halfVector); //法线与半向量的点积
float powerFactor=max(0.0,pow(nDotViewHalfVector,shininess)); //镜面反射光强度因子
vspecular=lightSpecular*powerFactor; //计算镜面光的最终强度
}
void main()
{
gl_Position = uMVPMatrix * vec4(aPosition,1); //根据总变换矩阵计算此次绘制此顶点位置
vec4 ambientTemp=vec4(0.0,0.0,0.0,0.0);
vec4 diffuseTemp=vec4(0.0,0.0,0.0,0.0);
vec4 specularTemp=vec4(0.0,0.0,0.0,0.0);
pointLight(normalize(aNormal),ambientTemp,diffuseTemp,specularTemp,uLightLocation,vec4(0.1,0.1,0.1,1.0),vec4(0.7,0.7,0.7,1.0),vec4(0.3,0.3,0.3,1.0));
vambient=ambientTemp;
vdiffuse=diffuseTemp;
vspecular=specularTemp;
}