Question

我使用OpenGL ES3开发Android的C ++项目，所以我尝试使用定向光来实现阴影贴图，我理解这个理论但是我从来没有成功渲染它。 Image describes the problem 首先我创建包含深度图的帧缓冲区：

glGenFramebuffers(1, &depthMapFBO);
glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
glGenTextures(1, &depthMap);
glBindTexture(GL_TEXTURE_2D, depthMap);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, SHADOW_WIDTH, SHADOW_HEIGHT, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthMap, 0);
glDrawBuffers(1, GL_NONE);
glReadBuffer(GL_NONE);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);

然后我创建一个着色器程序，编译深度着色器，如下所示：

#version 300 es
precision mediump float;

layout (location = 0) in vec3 position;
layout (location = 4) in ivec4 BoneIDs;
layout (location = 5) in vec4 Weights;

const int MAX_BONES = 100;

uniform mat4 lightSpaceMatrix;
uniform mat4 model;
uniform bool skinned;
uniform mat4 gBones[MAX_BONES];

void main(){
vec4 nPos;
if(skinned){
    mat4 BoneTransform = gBones[BoneIDs[0]] * Weights[0];
    BoneTransform     += gBones[BoneIDs[1]] * Weights[1];
    BoneTransform     += gBones[BoneIDs[2]] * Weights[2];
    BoneTransform     += gBones[BoneIDs[3]] * Weights[3];
    nPos=BoneTransform * vec4(position, 1.0);
}
else 
    nPos = vec4(position, 1.0);

vec4 p=model * nPos;
gl_Position = lightSpaceMatrix * p;
}

使用此着色器程序使用光空间矩阵绘制场景，使用以下内容：

glCullFace(GL_FRONT);
        double delta = GetCurrentTime() - firstFrame;
        glm::mat4 camInv = glm::inverse(camera->getViewMatrix());
        glm::mat4 lightSpaceProjection = glm::ortho(-40.0f, 40.0f, -40.0f, 40.0f, -1.0f, 100.0f);
        glm::mat4 lightSpaceView = glm::lookAt(sun->direction, glm::vec3(0, 0, 0), glm::vec3(0, 1, 0));
        lightSpaceMatrix = lightSpaceProjection * (lightSpaceView*camInv) ;
        glViewport(0, 0, SHADOW_WIDTH, SHADOW_HEIGHT);
        glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);

        glClear(GL_DEPTH_BUFFER_BIT);
        directDepthShader.use();
        glUniformMatrix4fv(glGetUniformLocation(directDepthShader.getProgramID(), "lightSpaceMatrix"), 1, GL_FALSE, glm::value_ptr(lightSpaceMatrix));
        for (mesh_it it = castShadowMeshes.begin(); it != castShadowMeshes.end(); it++) {
            it->get()->renderDepth(directDepthShader, delta);
        }
        glCullFace(GL_BACK);
glBindFramebuffer(GL_FRAMEBUFFER, 0);

最后，我使用常规着色器程序渲染场景，并使用以下代码将深度贴图绑定到shadowMap制服：

glViewport(0, 0, width, height);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
phongShader.use();
if (sun != nullptr)
    if (sun->castShadow)
        glUniformMatrix4fv(glGetUniformLocation(phongShader.getProgramID(), "lightSpaceMatrix"), 1, GL_FALSE, glm::value_ptr(lightSpaceMatrix));
this->setLightsUniforms(phongShader);
this->setViewUniforms(phongShader);
for (mesh_it it = phongMeshes.begin(); it != phongMeshes.end(); it++) {
    if (it->get()->hasNormalMap) {
        glUniform1i(glGetUniformLocation(phongShader.getProgramID(), "has_normal_map"), 1);
        if (directlights.size() > 0) {
            for (dlight_it it = this->directlights.begin(); it != this->directlights.end(); ++it) {
                GLuint directLightPosLoc = glGetUniformLocation(phongShader.getProgramID(), (const GLchar*) ("directLightPos[" + ToString((*it)->index) + "]").c_str());
                glUniform3f(directLightPosLoc, (*it)->direction.x, (*it)->direction.y, (*it)->direction.z);
            }
        }
        if (pointlights.size() > 0) {
            for (plight_it it = this->pointlights.begin(); it != this->pointlights.end(); ++it) {
                GLuint pointLightPosLoc = glGetUniformLocation(phongShader.getProgramID(), (const GLchar*) ("pointLightPos[" + ToString((*it)->index) + "]").c_str());
                glUniform3f(pointLightPosLoc, (*it)->position.x, (*it)->position.y, (*it)->position.z);
            }
        }
        if (spotlights.size() > 0) {
            for (slight_it it = this->spotlights.begin(); it != this->spotlights.end(); ++it) {
                GLuint spotLightPosLoc = glGetUniformLocation(phongShader.getProgramID(), (const GLchar*) ("spotLightPos[" + ToString((*it)->index) + "]").c_str());
                glUniform3f(spotLightPosLoc, (*it)->position.x, (*it)->position.y, (*it)->position.z);
            }
        }
    }
    double first = GetCurrentTime() - firstFrame;
    it->get()->textures = 0;
    if (sun != nullptr)
        if (sun->castShadow) {
            glUniform1i(glGetUniformLocation(phongShader.getProgramID(), "shadowMap"), it->get()->textures);
            glActiveTexture(GL_TEXTURE0 + it->get()->textures);
            glBindTexture(GL_TEXTURE_2D, depthMap);
            it->get()->textures++;
        }
    it->get()->Render(phongShader, first, deltaTime);
    glBindTexture(GL_TEXTURE_2D, 0);
}

最后，着色器顶点和片段如下：

顶点：

#version 300 es
precision mediump float;

#define NR_DIRECT_LIGHTS 0
#define NR_POINT_LIGHTS 0
#define NR_SPOT_LIGHTS 0

layout (location = 0) in vec3 position;
layout (location = 1) in vec3 normal;
layout (location = 2) in vec2 texCoord;
layout (location = 3) in vec3 tangent;
layout (location = 4) in ivec4 BoneIDs;
layout (location = 5) in vec4 Weights;

const int MAX_BONES = 100;

out vec2 TexCoords;
out vec3 Normal;
out vec3 tDirectLightPos[NR_DIRECT_LIGHTS];
out vec3 tPointLightPos[NR_POINT_LIGHTS];
out vec3 tSpotLightPos[NR_SPOT_LIGHTS];
out vec3 tViewPos;
out vec3 tFragPos;
out vec4 FragPosLightSpace;

// conditions //
uniform bool has_normal_map;    
uniform bool skinned;
//

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
uniform vec3 viewPos;
uniform mat4 lightSpaceMatrix;  
uniform mat4 gBones[MAX_BONES];

uniform vec3 directLightPos[NR_DIRECT_LIGHTS];
uniform vec3 pointLightPos[NR_POINT_LIGHTS];
uniform vec3 spotLightPos[NR_SPOT_LIGHTS];

void main(){    
    TexCoords = texCoord;
    vec4 nPos;
    vec3 N=transpose(inverse(mat3(model))) * normal;
    if(skinned){
        mat4 BoneTransform = gBones[BoneIDs[0]] * Weights[0];
        BoneTransform     += gBones[BoneIDs[1]] * Weights[1];
        BoneTransform     += gBones[BoneIDs[2]] * Weights[2];
        BoneTransform     += gBones[BoneIDs[3]] * Weights[3];
        nPos=BoneTransform * vec4(position, 1.0);   
        Normal=(BoneTransform*vec4(N,0.0)).xyz; 
    }
    else{
        nPos = vec4(position, 1.0);
        Normal=N;   
    }
    gl_Position = projection*view * model * nPos;

    vec3 FragPos = vec3(model * nPos);  
    if(has_normal_map){
        mat3 normalMatrix = transpose(inverse(mat3(model)));        
        vec3 T = normalize(normalMatrix * tangent);
        vec3 N = normalize(N);
        T = normalize(T - dot(T, N) * N);
        vec3 B = cross(N,T);    
        if (dot(cross(N, T), B) < 0.0)
           T = T * -1.0;    
        mat3 TBN = transpose(mat3(T, B, N));

        tViewPos=TBN*viewPos;
        tFragPos=TBN*FragPos;
        for(int i = 0; i < NR_DIRECT_LIGHTS-2; i++)
            tDirectLightPos[i]=TBN*directLightPos[i];
        for(int i = 0; i < NR_POINT_LIGHTS-2; i++)
            tPointLightPos[i]=TBN*pointLightPos[i];
        for(int i = 0; i < NR_SPOT_LIGHTS-2; i++)
            tSpotLightPos[i]=TBN*spotLightPos[i];
    }
    else{
        tViewPos=viewPos;
        tFragPos=FragPos;
    }
    FragPosLightSpace = lightSpaceMatrix * vec4(FragPos,1.0);       
}

片段：

#version 300 es
precision mediump float;

#define NR_DIRECT_LIGHTS 0
#define NR_POINT_LIGHTS 0
#define NR_SPOT_LIGHTS 0

out vec4 glFragColor;

vec2 poissonDisk[4] = vec2[](
vec2( -0.94201624, -0.39906216 ),
vec2( 0.94558609, -0.76890725 ),
vec2( -0.094184101, -0.92938870 ),
vec2( 0.34495938, 0.29387760 )
);
struct SpotLight{
    vec3 position;
    vec3 direction;
    vec3 color;

    float constant;
    float linear;
    float quadratic;
    float cutoff;
    float outerCutOff;
    float intensity;
    int castShadow;
};

struct PointLight{
    vec3 position;
    vec3 color;

    float constant;
    float linear;
    float quadratic;
    float intensity;
};

struct DirectLight {
    vec3 direction;
    vec3 color;
    float intensity;
    int castShadow;
};

in vec2 TexCoords;
in vec3 Normal;
in vec4 FragPosLightSpace;
in vec3 tDirectLightPos[NR_DIRECT_LIGHTS];
in vec3 tPointLightPos[NR_POINT_LIGHTS];
in vec3 tSpotLightPos[NR_SPOT_LIGHTS];
in vec3 tViewPos;
in vec3 tFragPos;

uniform bool Has_normal_map;

uniform sampler2D mat_diffuse;
uniform sampler2D mat_specular;
uniform sampler2D mat_normal;
uniform sampler2D shadowMap;

uniform vec3 matDiffuse;
uniform vec3 matSpecular;
uniform float shininess;

uniform float far_plane;

uniform DirectLight directLights[NR_DIRECT_LIGHTS];
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform SpotLight spotLights[NR_SPOT_LIGHTS];

vec3 calcDirectLight(DirectLight,vec3,vec3,vec3,vec3);
vec3 calcPointLight(PointLight,vec3,vec3,vec3,vec3);
vec3 calcSpotLight(SpotLight,vec3,vec3,vec3,vec3);
float directShadowCalculation();

void main(){
    vec3 normal;
    if(Has_normal_map){
        normal=texture(mat_normal, TexCoords).rgb;
        normal = normalize(normal * 2.0 - 1.0);  // this normal is in tangent space
    }
    else
        normal=normalize(Normal);

    vec3 diffColor= matDiffuse+vec3(texture(mat_diffuse, TexCoords));   
    vec3 specColor= matSpecular+vec3(texture(mat_specular,TexCoords));

    vec3 result;
    result=vec3(0.0);
    for(int i = 0; i < NR_DIRECT_LIGHTS-2; i++)
        result += calcDirectLight(directLights[i],normal,tDirectLightPos[i],diffColor,specColor);
    for(int i = 0; i < NR_POINT_LIGHTS-2; i++)
        result += calcPointLight(pointLights[i],normal,tPointLightPos[i],vec3(0.0,0.2,0.4),specColor);
    for(int i = 0; i < NR_SPOT_LIGHTS-2; i++)
        result += calcSpotLight(spotLights[i],normal,tSpotLightPos[i],diffColor,specColor);
    vec4 color =vec4(result,1.0);   
    float gamma = 2.2;
    color.rgb = pow(color.rgb, vec3(1.0/gamma));
    vec4 ambient=vec4(0.2,0.2,0.2,1.0)*vec4(diffColor,1.0);
    glFragColor=ambient+color;
}

vec3 calcDirectLight(DirectLight light,vec3 norm,vec3 tLightPos,vec3 diffColor,vec3 specColor){ 
    vec3 lightDir ;
    if(Has_normal_map)
        lightDir= normalize(tLightPos);
    else
        lightDir = normalize(light.direction);

    float diff = max(dot(lightDir,norm), 0.0);
    vec3 diffuse = light.color * diff *diffColor;

    vec3 viewDir = normalize(tViewPos- tFragPos);       
    vec3 halfwayDir = normalize(lightDir + viewDir);
    float spec = pow(max(dot(norm, halfwayDir), 0.0), 32.0);
    vec3 specular = shininess* spec *specColor* light.color;
    vec3 result;
    if(light.castShadow==1){
        float shadow = directShadowCalculation();
        result =light.intensity* ( shadow* (diffuse + specular));
    }
    else
        result =light.intensity* (diffuse + specular);
    return result;
}

vec3 calcPointLight(PointLight light,vec3 norm,vec3 tLightPos,vec3 diffColor,vec3 specColor){
    vec3 lightDir ;
    if(Has_normal_map)
        lightDir= normalize(tLightPos-tFragPos);
    else
        lightDir = normalize(light.position - tFragPos);
    float diff = max(dot(lightDir,norm), 0.0);
    vec3 diffuse = light.color * diff * diffColor;

    vec3 viewDir = normalize(tViewPos- tFragPos);
    vec3 halfwayDir = normalize(lightDir + viewDir);
    float spec = pow(max(dot(norm, halfwayDir), 0.0), 16.0);        
    vec3 specular =shininess* specColor * spec * light.color;

    vec3 result;
    float distance = length(light.position - tFragPos);
    float attenuation = 1.0f / (light.constant + light.linear * distance +light.quadratic * (distance * distance));
    diffuse *= attenuation;
    specular *= attenuation;
    result=light.intensity*(diffuse+specular);
    return result;
}

vec3 calcSpotLight(SpotLight light,vec3 norm,vec3 tLightPos,vec3 diffColor,vec3 specColor){                   
    vec3 lightDir ;
    if(Has_normal_map)
        lightDir= normalize(tLightPos-tFragPos);
    else
        lightDir = normalize(light.position - tFragPos);
    float diff = max(dot(lightDir,norm), 0.0);
    vec3 diffuse = light.color * diff * diffColor;

    vec3 viewDir = normalize(tViewPos- tFragPos);

    float spec =0.0;
    vec3 halfwayDir = normalize(lightDir + viewDir);
    spec = pow(max(dot(norm, halfwayDir), 0.0), 16.0);    
    vec3 specular = shininess* light.color * spec * specColor;

    // Spotlight (soft edges)
    float theta = dot(lightDir, normalize(-light.direction)); 
    float epsilon = (light.cutoff - light.outerCutOff);
    float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
    diffuse  *= intensity;
    specular *= intensity;

    // Attenuation
    float distance    = length(light.position - tFragPos);
    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
    diffuse  *= attenuation;
    specular *= attenuation;   

    vec3 result = intensity*(diffuse+specular);
    return result;
}

float directShadowCalculation(){
    vec3 projCoords = FragPosLightSpace.xyz / FragPosLightSpace.w;
    projCoords = projCoords * 0.5 + 0.5;
    float shadow = 1.0; 
    for (int i=0;i<4;i++){
        if ( texture( shadowMap, -projCoords.xy + poissonDisk[i]/700.0 ).z  <  -projCoords.z ){
           shadow-=0.2;
        }
    } 
    if(projCoords.z > 1.0)
        shadow = 0.0; 
    return shadow;
}

对不起所有代码，但我不知道问题出在哪里，需要一周的时间进行搜索和调试，没有任何进展。

编辑 1-光位置矢量为（-3.5f，8.0f，1.0f） 2-我将directShadowCalculation()更改为：

    float directShadowCalculation(){
    vec3 projCoords = FragPosLightSpace.xyz / FragPosLightSpace.w;
    projCoords = projCoords * 0.5 + 0.5;
    float shadow = 1.0; 
    for (int i=0;i<4;i++){
        if ( texture( shadowMap, projCoords.xy + poissonDisk[i]/700.0 ).z  <  projCoords.z ){
           shadow-=0.2;
        }
    } 
    if(projCoords.z > 1.0)
        shadow = 0.0; 
    return shadow;
}

这是结果

Answer 1

如果必须将视图空间坐标转换为光源的局部空间，则必须在设置lightSpaceMatrix时进行设置：

lightSpaceMatrix = lightSpaceProjection * (lightSpaceView*camInv)

因为，您必须按camInv从视图空间转换为世界空间。然后你必须转换世界空间坐标，从光源（lightSpaceView）看。最后你必须预测它lightSpaceProjection。

但您可以在顶点着色器中直接从世界坐标转换为光源的局部空间：

FragPosLightSpace = lightSpaceMatrix * vec4(FragPos,1.0);

因此你必须像这样设置lightSpaceMatrix：

lightSpaceMatrix = lightSpaceProjection * lightSpaceView

投影矩阵描述了从场景的3D点到视口的2D点的映射。它从视图（眼睛）空间转换到剪辑空间，并且通过用剪辑坐标的 w 分量进行划分，将剪辑空间中的坐标转换为规范化设备坐标（NDC）。 NDC在（-1，-1，-1）到（1,1,1）的范围内。这与正投影或透视投影无关。

将投影的片段位置（光照空间）除以其 w 分量后，projCoords的范围为（-1，-1，-1）到（1， 1,1）。 projCoords = projCoords * 0.5 + 0.5;将XY坐标转换为纹理坐标，并将Z坐标转换为[0,1]范围内的深度值。

vec3 projCoords = FragPosLightSpace.xyz / FragPosLightSpace.w;
projCoords = projCoords * 0.5 + 0.5;

阴影测试中的反转没有意义，因为纹理的内容也应该是[0,1]范围内的深度值。
阴影测试应该看起来像这样：

if ( texture( shadowMap, projCoords.xy ).z < projCoords.z )
{
    ....
}

如果sun->direction是朝向太阳的方向，那么lightSpaceView必须像这样设置：

glm::mat4 lightSpaceView = glm::lookAt(sun->direction, glm::vec3(0, 0, 0), glm::vec3(0, 1, 0));

但是，如果sun->direction是太阳照射的方向，那么lightSpaceView必须像这样设置：

glm::mat4 lightSpaceView = glm::lookAt(-sun->direction, glm::vec3(0, 0, 0), glm::vec3(0, 1, 0));

由于您对光使用正交投影并且光空间矩阵的原点靠近世界空间的原点，因此光投影的近平面应远离光空间的背面。否则，在生成光照深度图时，光投影的近平面将会剪切接近太阳的物体。

glm::mat4 lightSpaceProjection = glm::ortho(-40.0f, 40.0f, -40.0f, 40.0f, -100.0f, 100.0f);

由于灯光计算是在视图空间中完成的，因此您必须将灯光位置从世界空间转换为视图空间：

GLuint directLightPosLoc = glGetUniformLocation(phongShader.getProgramID(), (const GLchar*) ("directLightPos[" + ToString((*it)->index) + "]").c_str());
glm::vec3 dir = glm::mat3(camera->getViewMatrix()) * (*it)->direction;
glUniform3fv( directLightPosLoc, 1, &dir[0] );


GLuint pointLightPosLoc = glGetUniformLocation(phongShader.getProgramID(), (const GLchar*) ("pointLightPos[" + ToString((*it)->index) + "]").c_str());
glm::vec4 pos = camera->getViewMatrix( * glm::vec4((*it)->position.x, (*it)->position.y, (*it)->position.z, 1.0);
glUniform3fv( directLightPosLoc, 1, &pos[0] );


GLuint spotLightPosLoc = glGetUniformLocation(phongShader.getProgramID(), (const GLchar*) ("spotLightPos[" + ToString((*it)->index) + "]").c_str());
glm::vec4 pos = camera->getViewMatrix( * glm::vec4((*it)->position.x, (*it)->position.y, (*it)->position.z, 1.0);
glUniform3fv( spotLightPosLoc, 1, &pos[0] );

请参阅演示算法的WebGL示例：

＆＃13;

(function loadscene() {

var sliderScale = 100.0
var gl;
var progShadow;
var progDraw;
var shadowFB;
var bufTorus;
var bufGround;
var canvas;
var vp_size;
var fb_size;

function render(deltaMS){

var ambient = document.getElementById( "ambient" ).value / sliderScale;
var diffuse = document.getElementById( "diffuse" ).value / sliderScale;
var specular = document.getElementById( "specular" ).value / sliderScale;
var shininess = document.getElementById( "shininess" ).value;

canvas = document.getElementById( "scene-canvas" );

var lightPos = [-3.0, 0.0, 2.0];
var lightAnimationMat = RotateAxis( IdentityMat44(), CalcAng( deltaMS, 20.0 ), 2 );
lightPos = Transform( lightPos, lightAnimationMat );
var lightDir = [ -lightPos[0], -lightPos[1], -lightPos[2] ];
var light  = Camera.Create( lightPos, [0, 0, 0], [0, 0, 1], 110, [ 5.0, 5.0 ], -20.0, 20.0 );
var camera = Camera.Create( [0, 2.5, 2], [0, 0, 0], [0, 0, 1], 110, [vp_size[0], vp_size[1]], 0.5, 100.0 );

var lightPrjMat = Camera.Ortho( light );
var lightViewMat = Camera.LookAt( light );
var prjMat = Camera.Perspective( camera );
var viewMat = Camera.LookAt( camera );
var modelMat = IdentityMat44();
modelMat = RotateAxis( modelMat, CalcAng( deltaMS, 13.0 ), 0 );
modelMat = RotateAxis( modelMat, CalcAng( deltaMS, 17.0 ), 1 );
groundModelMat = IdentityMat44();
var viewLightDir = TransformVec( lightDir, viewMat );
    
gl.viewport( 0, 0, fb_size[0], fb_size[1] );
gl.enable( gl.DEPTH_TEST );

shadowFB.Bind( true );
ShaderProgram.Use( progShadow );
ShaderProgram.SetUniformM44( progShadow, "u_projectionMat44", lightPrjMat );
ShaderProgram.SetUniformM44( progShadow, "u_viewMat44", lightViewMat );
ShaderProgram.SetUniformM44( progShadow, "u_modelMat44", modelMat );
ShaderProgram.SetUniformF2( progShadow, "u_depthRange", [light.near, light.far] );

VertexBuffer.Draw( bufTorus );

gl.viewport( 0, 0, vp_size[0], vp_size[1] );
shadowFB.Release( true );
shadowFB.BindTexture( 1 );
ShaderProgram.Use( progDraw );
ShaderProgram.SetUniformM44( progDraw, "u_projectionMat44", prjMat );
ShaderProgram.SetUniformM44( progDraw, "u_viewMat44", viewMat );
ShaderProgram.SetUniformM44( progDraw, "u_lightProjectionMat44", lightPrjMat );
ShaderProgram.SetUniformM44( progDraw, "u_lightViewMat44", lightViewMat );
ShaderProgram.SetUniformM44( progDraw, "u_modelMat44", modelMat );
ShaderProgram.SetUniformI1( progDraw, "u_depthSampler", 1 );
ShaderProgram.SetUniformF3( progDraw, "u_lightDir", viewLightDir )
ShaderProgram.SetUniformF1( progDraw, "u_ambient", ambient )
ShaderProgram.SetUniformF1( progDraw, "u_diffuse", diffuse )
ShaderProgram.SetUniformF1( progDraw, "u_specular", specular )
ShaderProgram.SetUniformF1( progDraw, "u_shininess", shininess )

VertexBuffer.Draw( bufTorus );
ShaderProgram.SetUniformM44( progDraw, "u_modelMat44", groundModelMat );
VertexBuffer.Draw( bufGround );

requestAnimationFrame(render);
}

function nearestPow2( aSize ){
  return Math.pow( 2, Math.round( Math.log( aSize ) / Math.log( 2 ) ) ); 
}

function resize() {
    //vp_size = [gl.drawingBufferWidth, gl.drawingBufferHeight];
    vp_size = [window.innerWidth, window.innerHeight]
    canvas.width = vp_size[0];
    canvas.height = vp_size[1];

    var size = Math.max(256, Math.max(vp_size[0], vp_size[1]));
    size = nearestPow2(size/2);
    fb_size = [size, size]
    shadowFB = FrameBuffer.Create( fb_size ); 
}

function initScene() {

document.getElementById( "ambient" ).value = 0.2 * sliderScale;
document.getElementById( "diffuse" ).value = 0.7 * sliderScale;
document.getElementById( "specular" ).value = 0.5 * sliderScale;
document.getElementById( "shininess" ).value = 8.0;

canvas = document.getElementById( "scene-canvas");
vp_size = [canvas.width, canvas.height];
gl = canvas.getContext( "experimental-webgl" );
if ( !gl )
  return;

progShadow = ShaderProgram.Create( 
[ { source : "shadow-shader-vs", stage : gl.VERTEX_SHADER },
{ source : "shadow-shader-fs", stage : gl.FRAGMENT_SHADER }
] );
if (!progShadow.progObj)
    return null;
progShadow.inPos = ShaderProgram.AttributeIndex( progShadow, "inPos" );
progShadow.inNV  = ShaderProgram.AttributeIndex( progShadow, "inNV" );
progShadow.inCol = ShaderProgram.AttributeIndex( progShadow, "inCol" );

progDraw = ShaderProgram.Create( 
  [ { source : "draw-shader-vs", stage : gl.VERTEX_SHADER },
    { source : "draw-shader-fs", stage : gl.FRAGMENT_SHADER }
  ] );
if (!progDraw.progObj)
    return null;
progDraw.inPos = ShaderProgram.AttributeIndex( progDraw, "inPos" );
progDraw.inNV  = ShaderProgram.AttributeIndex( progDraw, "inNV" );
progDraw.inCol = ShaderProgram.AttributeIndex( progDraw, "inCol" );

// create torus
var circum_size = 32, tube_size = 32;
var rad_circum = 1.0;
var rad_tube = 0.5;
var torus_pts = [];
var torus_nv = [];
var torus_col = [];
var torus_inx = [];
var col = [1, 0.5, 0.0];
for ( var i_c = 0; i_c < circum_size; ++ i_c ) {
    var center = [
        Math.cos(2 * Math.PI * i_c / circum_size),
        Math.sin(2 * Math.PI * i_c / circum_size) ]
    for ( var i_t = 0; i_t < tube_size; ++ i_t ) {
        var tubeX = Math.cos(2 * Math.PI * i_t / tube_size)
        var tubeY = Math.sin(2 * Math.PI * i_t / tube_size)
        var pt = [
            center[0] * ( rad_circum + tubeX * rad_tube ),
            center[1] * ( rad_circum + tubeX * rad_tube ),
            tubeY * rad_tube ]
        var nv = [ pt[0] - center[0] * rad_tube, pt[1] - center[1] * rad_tube, tubeY * rad_tube ]
        torus_pts.push( pt[0], pt[1], pt[2] );
        torus_nv.push( nv[0], nv[1], nv[2] );
        torus_col.push( col[0], col[1], col[2] );
        var i_cn = (i_c+1) % circum_size
        var i_tn = (i_t+1) % tube_size
        var i_c0 = i_c * tube_size; 
        var i_c1 = i_cn * tube_size; 
        torus_inx.push( i_c0+i_t, i_c0+i_tn, i_c1+i_t, i_c0+i_tn, i_c1+i_t, i_c1+i_tn )
    }
}
bufTorus = VertexBuffer.Create(
  [ { data : torus_pts, attrSize : 3, attrLoc : progDraw.inPos },
    { data : torus_nv,  attrSize : 3, attrLoc : progDraw.inNV },
    { data : torus_col, attrSize : 3, attrLoc : progDraw.inCol } ],
    torus_inx
);

var g_l = 8.0;
var g_h = -2.5;
var g_c = [ 0.8, 0.6, 0.8 ];
bufGround = VertexBuffer.Create( 
    [ { data : [ -g_l, -g_l, g_h, g_l, -g_l, g_h, g_l, g_l, g_h, -g_l, g_l, g_h ], attrSize : 3, attrLoc : progDraw.inPos },
      { data : [ 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0 ], attrSize : 3, attrLoc : progDraw.inNV },
      { data : [ g_c[0], g_c[1], g_c[2], g_c[0], g_c[1], g_c[2], g_c[0], g_c[1], g_c[2], g_c[0], g_c[1], g_c[2] ], attrSize : 3, attrLoc : progDraw.inCol } ],
    [ 0, 1, 2, 0, 2, 3 ]
);

window.onresize = resize;
resize();
requestAnimationFrame(render);
}

var startTime;
function Fract( val ) { 
    return val - Math.trunc( val );
}
function CalcAng( deltaTime, intervall ) {
    return Fract( deltaTime / (1000*intervall) ) * 2.0 * Math.PI;
}

function IdentityMat44() { return [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]; }

function RotateAxis(matA, angRad, axis) {
    var aMap = [ [1, 2], [2, 0], [0, 1] ];
    var a0 = aMap[axis][0], a1 = aMap[axis][1]; 
    var sinAng = Math.sin(angRad), cosAng = Math.cos(angRad);
    var matB = IdentityMat44();
    for ( var i = 0; i < 16; ++ i ) matB[i] = matA[i];
    for ( var i = 0; i < 3; ++ i ) {
        matB[a0*4+i] = matA[a0*4+i] * cosAng + matA[a1*4+i] * sinAng;
        matB[a1*4+i] = matA[a0*4+i] * -sinAng + matA[a1*4+i] * cosAng;
    }
    return matB;
}

function Cross( a, b ) { return [ a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0], 0.0 ]; }
function Dot( a, b ) { return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; }
function Normalize( v ) {
    var len = Math.sqrt( v[0] * v[0] + v[1] * v[1] + v[2] * v[2] );
    return [ v[0] / len, v[1] / len, v[2] / len ];
}

Transform = function(vec, mat) {
    return [
        vec[0] * mat[0*4+0] + vec[1] * mat[1*4+0] + vec[2] * mat[2*4+0] + mat[3*4+0],
        vec[0] * mat[0*4+1] + vec[1] * mat[1*4+1] + vec[2] * mat[2*4+1] + mat[3*4+1],
        vec[0] * mat[0*4+2] + vec[1] * mat[1*4+2] + vec[2] * mat[2*4+2] + mat[3*4+2],
        vec[0] * mat[0*4+3] + vec[1] * mat[1*4+3] + vec[2] * mat[2*4+3] + mat[3*4+3] ]
    if ( h[3] == 0.0 )
        return [0, 0, 0]
    return [ h[0]/h[3], h[1]/h[3], h[2]/h[3] ];
}

TransformVec = function(vec, mat) {
   return [
        vec[0] * mat[0*4+0] + vec[1] * mat[1*4+0] + vec[2] * mat[2*4+0],
        vec[0] * mat[0*4+1] + vec[1] * mat[1*4+1] + vec[2] * mat[2*4+1],
        vec[0] * mat[0*4+2] + vec[1] * mat[1*4+2] + vec[2] * mat[2*4+2] ]
}

var Camera = {};
Camera.Create = function( pos, target, up, fov_y, vp, near, far ) {
    var camera = {};
    camera.pos    = pos;
    camera.target = target;
    camera.up     = up;
    camera.fov_y  = fov_y;
    camera.vp     = vp;
    camera.near   = near;
    camera.far    = far;
    return camera;
}
Camera.Ortho = function( camera ) {
    var fn = camera.far + camera.near;
    var f_n = camera.far - camera.near;
    var w = camera.vp[0];
    var h = camera.vp[1];
    var m = IdentityMat44();
    m[0]  = 2 / w; m[1]  = 0;     m[2]  =  0;        m[3]  = 0;
    m[4]  = 0;     m[5]  = 2 / h; m[6]  =  0;        m[7]  = 0;
    m[8]  = 0;     m[9]  = 0;     m[10] = -2 / f_n;  m[11] = 0;
    m[12] = 0;     m[13] = 0;     m[14] = -fn / f_n; m[15] = 1;
    return m;
}
Camera.Perspective = function( camera ) {
    var fn = camera.far + camera.near;
    var f_n = camera.far - camera.near;
    var r = camera.vp[0] / camera.vp[1];
    var t = 1 / Math.tan( Math.PI * camera.fov_y / 360 );
    var m = IdentityMat44();
    m[0]  = t/r; m[1]  = 0; m[2]  =  0;                              m[3]  = 0;
    m[4]  = 0;   m[5]  = t; m[6]  =  0;                              m[7]  = 0;
    m[8]  = 0;   m[9]  = 0; m[10] = -fn / f_n;                       m[11] = -1;
    m[12] = 0;   m[13] = 0; m[14] = -2 * camera.far * camera.near / f_n; m[15] =  0;
    return m;
}
Camera.LookAt = function( camera ) {
    var mz = Normalize( [ camera.pos[0]-camera.target[0], camera.pos[1]-camera.target[1], camera.pos[2]-camera.target[2] ] );
    var mx = Normalize( Cross( camera.up, mz ) );
    var my = Normalize( Cross( mz, mx ) );
    var tx = Dot( mx, camera.pos );
    var ty = Dot( my, camera.pos );
    var tz = Dot( [-mz[0], -mz[1], -mz[2]], camera.pos ); 
    var m = IdentityMat44();
    m[0]  = mx[0]; m[1]  = my[0]; m[2]  = mz[0]; m[3]  = 0;
    m[4]  = mx[1]; m[5]  = my[1]; m[6]  = mz[1]; m[7]  = 0;
    m[8]  = mx[2]; m[9]  = my[2]; m[10] = mz[2]; m[11] = 0;
    m[12] = tx;    m[13] = ty;    m[14] = tz;    m[15] = 1; 
    return m;
} 

var ShaderProgram = {};
ShaderProgram.Create = function (shaderList) {
    var shaderObjs = [];
    for (var i_sh = 0; i_sh < shaderList.length; ++i_sh) {
        var shderObj = this.CompileShader(shaderList[i_sh].source, shaderList[i_sh].stage);
        if (shderObj == 0)
            return 0;
        shaderObjs.push(shderObj);
    }
    var prog = {}
    prog.progObj = this.LinkProgram(shaderObjs)
    if (prog.progObj) {
        prog.attribIndex = {};
        var noOfAttributes = gl.getProgramParameter(prog.progObj, gl.ACTIVE_ATTRIBUTES);
        for (var i_n = 0; i_n < noOfAttributes; ++i_n) {
            var name = gl.getActiveAttrib(prog.progObj, i_n).name;
            prog.attribIndex[name] = gl.getAttribLocation(prog.progObj, name);
        }
        prog.unifomLocation = {};
        var noOfUniforms = gl.getProgramParameter(prog.progObj, gl.ACTIVE_UNIFORMS);
        for (var i_n = 0; i_n < noOfUniforms; ++i_n) {
            var name = gl.getActiveUniform(prog.progObj, i_n).name;
            prog.unifomLocation[name] = gl.getUniformLocation(prog.progObj, name);
        }
    }
    return prog;
}
ShaderProgram.AttributeIndex = function (prog, name) { return prog.attribIndex[name]; }
ShaderProgram.UniformLocation = function (prog, name) { return prog.unifomLocation[name]; }
ShaderProgram.Use = function (prog) { gl.useProgram(prog.progObj); }
ShaderProgram.SetUniformI1 = function (prog, name, val) { if (prog.unifomLocation[name]) gl.uniform1i(prog.unifomLocation[name], val); }
ShaderProgram.SetUniformF1 = function (prog, name, val) { if (prog.unifomLocation[name]) gl.uniform1f(prog.unifomLocation[name], val); }
ShaderProgram.SetUniformF2 = function (prog, name, arr) { if (prog.unifomLocation[name]) gl.uniform2fv(prog.unifomLocation[name], arr); }
ShaderProgram.SetUniformF3 = function (prog, name, arr) { if (prog.unifomLocation[name]) gl.uniform3fv(prog.unifomLocation[name], arr); }
ShaderProgram.SetUniformF4 = function (prog, name, arr) { if (prog.unifomLocation[name]) gl.uniform4fv(prog.unifomLocation[name], arr); }
ShaderProgram.SetUniformM33 = function (prog, name, mat) { if (prog.unifomLocation[name]) gl.uniformMatrix3fv(prog.unifomLocation[name], false, mat); }
ShaderProgram.SetUniformM44 = function (prog, name, mat) { if (prog.unifomLocation[name]) gl.uniformMatrix4fv(prog.unifomLocation[name], false, mat); }
ShaderProgram.CompileShader = function (source, shaderStage) {
    var shaderScript = document.getElementById(source);
    if (shaderScript)
        source = shaderScript.text;
    var shaderObj = gl.createShader(shaderStage);
    gl.shaderSource(shaderObj, source);
    gl.compileShader(shaderObj);
    var status = gl.getShaderParameter(shaderObj, gl.COMPILE_STATUS);
    if (!status) alert(gl.getShaderInfoLog(shaderObj));
    return status ? shaderObj : null;
}
ShaderProgram.LinkProgram = function (shaderObjs) {
    var prog = gl.createProgram();
    for (var i_sh = 0; i_sh < shaderObjs.length; ++i_sh)
        gl.attachShader(prog, shaderObjs[i_sh]);
    gl.linkProgram(prog);
    status = gl.getProgramParameter(prog, gl.LINK_STATUS);
    if (!status) alert("Could not initialise shaders");
    gl.useProgram(null);
    return status ? prog : null;
}

var VertexBuffer = {};
VertexBuffer.Create = function( attributes, indices ) {
    var buffer = {};
    buffer.buf = [];
    buffer.attr = []
    for ( var i = 0; i < attributes.length; ++ i ) {
        buffer.buf.push( gl.createBuffer() );
        buffer.attr.push( { size : attributes[i].attrSize, loc : attributes[i].attrLoc } );
        gl.bindBuffer( gl.ARRAY_BUFFER, buffer.buf[i] );
        gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( attributes[i].data ), gl.STATIC_DRAW );
    }
    buffer.inx = gl.createBuffer();
    gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, buffer.inx );
    gl.bufferData( gl.ELEMENT_ARRAY_BUFFER, new Uint16Array( indices ), gl.STATIC_DRAW );
    buffer.inxLen = indices.length;
    gl.bindBuffer( gl.ARRAY_BUFFER, null );
    gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, null );
    return buffer;
}
VertexBuffer.Draw = function( bufObj ) {
  for ( var i = 0; i < bufObj.buf.length; ++ i ) {
        gl.bindBuffer( gl.ARRAY_BUFFER, bufObj.buf[i] );
        gl.vertexAttribPointer( bufObj.attr[i].loc, bufObj.attr[i].size, gl.FLOAT, false, 0, 0 );
        gl.enableVertexAttribArray( bufObj.attr[i].loc );
    }
    gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, bufObj.inx );
    gl.drawElements( gl.TRIANGLES, bufObj.inxLen, gl.UNSIGNED_SHORT, 0 );
    for ( var i = 0; i < bufObj.buf.length; ++ i )
       gl.disableVertexAttribArray( bufObj.attr[i].loc );
    gl.bindBuffer( gl.ARRAY_BUFFER, null );
    gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, null );
}

var FrameBuffer = {};
FrameBuffer.Create = function( vp, texturePlan ) {
    var texPlan = texturePlan ? new Uint8Array( texturePlan ) : null;
    var fb = gl.createFramebuffer();
    var fbsize = Math.max(vp[0], vp[1]);
    fbsize = 1 << 31 - Math.clz32(fbsize); // nearest power of 2
    fb.width = fbsize;
    fb.height = fbsize;
    gl.bindFramebuffer( gl.FRAMEBUFFER, fb );
    fb.color0_texture = gl.createTexture();
    gl.bindTexture( gl.TEXTURE_2D, fb.color0_texture );
    gl.texImage2D( gl.TEXTURE_2D, 0, gl.RGBA, fb.width, fb.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, texPlan );
    gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST );
    gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST );
    gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE );
    gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE );
    fb.renderbuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer( gl.RENDERBUFFER, fb.renderbuffer );
    gl.renderbufferStorage( gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, fb.width, fb.height );
    gl.framebufferTexture2D( gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, fb.color0_texture, 0 );
    gl.framebufferRenderbuffer( gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, fb.renderbuffer );
    gl.bindTexture( gl.TEXTURE_2D, null );
    gl.bindRenderbuffer( gl.RENDERBUFFER, null );
    gl.bindFramebuffer( gl.FRAMEBUFFER, null );

    fb.Bind = function( clear ) {
        gl.bindFramebuffer( gl.FRAMEBUFFER, this );
        if ( clear ) {
            gl.clearColor( 0.0, 0.0, 0.0, 1.0 );
            gl.clear( gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT );
        }
    };

    fb.Release = function( clear ) {
        gl.bindFramebuffer( gl.FRAMEBUFFER, null );
        if ( clear ) {
            gl.clearColor( 0.0, 0.0, 0.0, 1.0 );
            gl.clear( gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT );
        }
    };

    fb.BindTexture = function( textureUnit ) {
        gl.activeTexture( gl.TEXTURE0 + textureUnit );
        gl.bindTexture( gl.TEXTURE_2D, this.color0_texture );
    };

    return fb;
}

initScene();
  
})();

＆＃13;

html,body {
    height: 100%;
    width: 100%;
    margin: 0;
    overflow: hidden;
}

#gui {
    position : absolute;
    top : 0;
    left : 0;
}

＆＃13;

<script id="shadow-shader-vs" type="x-shader/x-vertex">
  precision mediump float;
  
  attribute vec3 inPos;
  attribute vec3 inNV;
  attribute vec3 inCol;
  
  varying vec3 vertPos;
  varying vec3 vertNV;
  varying vec3 vertCol;
  varying vec4 vPosPrj;
  
  uniform mat4 u_projectionMat44;
  uniform mat4 u_viewMat44;
  uniform mat4 u_modelMat44;
  
  void main()
  {
      vec3 modelNV  = mat3( u_modelMat44 ) * normalize( inNV );
      vertNV        = mat3( u_viewMat44 ) * modelNV;
      vertCol       = inCol;
      vec4 modelPos = u_modelMat44 * vec4( inPos, 1.0 );
      vec4 viewPos  = u_viewMat44 * modelPos;
      vertPos       = viewPos.xyz / viewPos.w;
      vPosPrj       = u_projectionMat44 * viewPos;
      gl_Position   = vPosPrj;
  }
</script>

<script id="shadow-shader-fs" type="x-shader/x-fragment">
    precision mediump float;
    
    varying vec3 vertPos;
    varying vec3 vertNV;
    varying vec3 vertCol;
    varying vec4 vPosPrj;

    uniform vec2 u_depthRange;

    vec3 PackDepth( in float depth )
    {
        float depthVal = depth * (256.0*256.0*256.0 - 1.0) / (256.0*256.0*256.0);
        vec4 encode = fract( depthVal * vec4(1.0, 256.0, 256.0*256.0, 256.0*256.0*256.0) );
        return encode.xyz - encode.yzw / 256.0 + 1.0/512.0;
    }
    
    void main()
    {
        float ndc_depth = vPosPrj.z / vPosPrj.w;
        float nearZ     = u_depthRange.x;
        float farZ      = u_depthRange.y;
        float depth     = ndc_depth * 0.5 + 0.5;
        gl_FragColor    = vec4( PackDepth( depth ).xyz, 1.0 );
    }
</script>

<script id="draw-shader-vs" type="x-shader/x-vertex">
precision mediump float;

attribute vec3 inPos;
attribute vec3 inNV;
attribute vec3 inCol;

varying vec3 vertPos;
varying vec3 vertNV;
varying vec3 vertCol;
varying vec4 lightPrj;
varying vec4 vPosPrj;

uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
uniform mat4 u_lightProjectionMat44;
uniform mat4 u_lightViewMat44;

void main()
{
    vec3 modelNV  = mat3( u_modelMat44 ) * normalize( inNV );
    vertNV        = mat3( u_viewMat44 ) * modelNV;
    vertCol       = inCol;
    vec4 modelPos = u_modelMat44 * vec4( inPos, 1.0 );
    vec4 lightPos = u_lightViewMat44 * modelPos;
    vec4 viewPos  = u_viewMat44 * modelPos;
    lightPrj      = u_lightProjectionMat44 * lightPos;
    vertPos       = viewPos.xyz / viewPos.w;
    vPosPrj       = u_projectionMat44 * viewPos;
    gl_Position   = vPosPrj;
}
</script>
  
<script id="draw-shader-fs" type="x-shader/x-fragment">
precision mediump float;

varying vec3 vertPos;
varying vec3 vertNV;
varying vec3 vertCol;
varying vec4 lightPrj;
varying vec4 vPosPrj;

uniform sampler2D u_depthSampler;
uniform vec3      u_lightDir;
uniform float     u_ambient;
uniform float     u_diffuse;
uniform float     u_specular;
uniform float     u_shininess;

float UnpackDepth( in vec3 pack )
{
  float depth = dot( pack, 1.0 / vec3(1.0, 256.0, 256.0*256.0) );
  return depth * (256.0*256.0*256.0) / (256.0*256.0*256.0 - 1.0);
}

float Depth( in sampler2D depthSampler, in vec2 texC )
{
  vec3 depthVal = texture2D( depthSampler, texC.st ).xyz;  
  return UnpackDepth( depthVal.rgb );
}

void main()
{
    vec3  ndc_light  = lightPrj.xyz / lightPrj.w;
    vec2  lightTexC  = ndc_light.xy * 0.5 + 0.5;
    float lightDepth = ndc_light.z * 0.5 + 0.5;
    float testDepth  = Depth( u_depthSampler, lightTexC );
    float shadow     = step( lightDepth-0.01, testDepth ) + step( testDepth, 0.0 );
    vec3  color      = vertCol;
    vec3  lightCol   = u_ambient * color;
    vec3  normalV    = normalize( vertNV );
    vec3  lightV     = normalize( -u_lightDir );
    float NdotL      = max( 0.0, dot( normalV, lightV ) );
    lightCol        += shadow * NdotL * u_diffuse * color;
    vec3  eyeV       = normalize( -vertPos );
    vec3  halfV      = normalize( eyeV + lightV );
    float NdotH      = max( 0.0, dot( normalV, halfV ) );
    float kSpecular  = ( u_shininess + 2.0 ) * pow( NdotH, u_shininess ) / ( 2.0 * 3.14159265 );
    lightCol        += shadow * kSpecular * u_specular * color;
    gl_FragColor     = vec4( lightCol.rgb, 1.0 );
}
</script>

<div><form id="gui" name="inputs"><table>
    <tr> <td> <font color= #CCF>ambient</font> </td> 
            <td> <input type="range" id="ambient" min="0" max="100" value="0"/></td> </tr>
    <tr> <td> <font color= #CCF>diffuse</font> </td> 
            <td> <input type="range" id="diffuse" min="0" max="100" value="0"/></td> </tr>
    <tr> <td> <font color= #CCF>specular</font> </td> 
            <td> <input type="range" id="specular" min="0" max="100" value="0"/></td> </tr>
    <tr> <td> <font color= #CCF>shininess</font> </td> 
            <td> <input type="range" id="shininess" min="0" max="100" value="0"/></td> </tr>
</table></form></div>

<canvas id="scene-canvas" style="border: none;" width="512" height="512"></canvas>

＆＃13;

另见

OpenGL ES3阴影贴图问题

1 个答案: