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GLSL、Opengl 中的视差贴图问题

发布于 2024-10-13 00:06:17 字数 7951 浏览 8 评论 0原文

我的视差贴图给出了错误的结果。我不知道出了什么问题。

替代文本

替代文本

“阴影”位于错误的位置。

光线从观察者处指向立方体。 着色器程序（基于 dhpoware.com）：

[vert]
     varying vec3 lightDir;            
     varying vec3 viewDir;
     attribute vec4 tangent;
     void main() 
     { 
     gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
     gl_TexCoord[0] = gl_MultiTexCoord0;
     vec3 vertexPos = vec3(gl_ModelViewMatrix * gl_Vertex);
     vec3 n = normalize(gl_NormalMatrix * gl_Normal);
     vec3 t = normalize(gl_NormalMatrix * tangent.xyz);
     vec3 b = cross(n, t) * tangent.w;
     mat3 tbnMatrix = mat3(t.x, b.x, n.x,
                           t.y, b.y, n.y,
                           t.z, b.z, n.z);
     lightDir = (gl_LightSource[0].position.xyz - vertexPos) / 1000.0;
     lightDir = tbnMatrix * lightDir;
     viewDir = -vertexPos;
     viewDir = tbnMatrix * viewDir;
     } 

    [frag]
     varying vec3 lightDir;            
     varying vec3 viewDir;
     uniform sampler2D diffuseMap;
     uniform sampler2D normalMap;
     uniform sampler2D heightMap;
     uniform float scale;
     uniform float bias;
     void main() 
     { 
     vec3 v = normalize(viewDir);
     vec2 TexCoord = gl_TexCoord[0].st;
    {
     float height = texture2D(heightMap, gl_TexCoord[0].st).r;
     height = height * scale + bias;
     TexCoord = gl_TexCoord[0].st + (height * v.xy); 
    }
     vec3 l = lightDir;
     float atten = max(0.0, 1.0 - dot(l, l));
     l = normalize(l);
     vec3 n = normalize(texture2D(normalMap, TexCoord).rgb * 2.0 - 1.0);
     vec3 h = normalize(l + v);
     float nDotL = max(0.0, dot(n, l));
     float nDotH = max(0.0, dot(n, h));
     float power = (nDotL == 0.0) ? 0.0 : pow(nDotH, gl_FrontMaterial.shininess);
     vec4 ambient = gl_FrontLightProduct[0].ambient * atten;
     vec4 diffuse = gl_FrontLightProduct[0].diffuse * nDotL * atten;
     vec4 specular = gl_FrontLightProduct[0].specular * power * atten;
     vec4 color = gl_FrontLightModelProduct.sceneColor + ambient + diffuse + specular;color *= texture2D(diffuseMap,TexCoord);
     gl_FragColor = color ;
     }

来自立方体内容的日志（包括切线，第四个组成部分是用手习惯）：

------------------------------------------------------------------------------------------------------------------
VecContainer<Vertex> vertices = 

size: 36
space: 36
{
-4.000000, -4.000000, -4.000000, 
-4.000000, 4.000000, -4.000000, 
4.000000, 4.000000, -4.000000, 
4.000000, 4.000000, -4.000000, 
4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
4.000000, -4.000000, -4.000000, 
4.000000, -4.000000, 4.000000, 
4.000000, -4.000000, 4.000000, 
-4.000000, -4.000000, 4.000000, 
-4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, 4.000000, 
-4.000000, 4.000000, 4.000000, 
-4.000000, 4.000000, 4.000000, 
-4.000000, 4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
4.000000, -4.000000, -4.000000, 
4.000000, 4.000000, -4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, -4.000000, 4.000000, 
4.000000, -4.000000, -4.000000, 
-4.000000, 4.000000, -4.000000, 
-4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, -4.000000, 
-4.000000, 4.000000, -4.000000, 
-4.000000, -4.000000, 4.000000, 
4.000000, -4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
-4.000000, 4.000000, 4.000000, 
-4.000000, -4.000000, 4.000000, 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<Vertex> texcoords = 

size: 36
space: 36
{
0.000000, 0.000000, 
0.000000, 1.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
1.000000, 0.000000, 
0.000000, 0.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<Vertex> normals = 

size: 36
space: 36
{
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<tangent>* tangents = 

size: 36
space: 36
{
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, -0.000000, -1.000000, 
1.000000, 0.000000, -0.000000, -1.000000, 
1.000000, 0.000000, -0.000000, -1.000000 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<GLuint> indices = 

size: 12
space: 12
{
3, 4, 5, 
6, 7, 8, 
9, 10, 11, 
12, 13, 14, 
15, 16, 17, 
18, 19, 20, 
21, 22, 23, 
24, 25, 26, 
27, 28, 29, 
30, 31, 32, 
33, 34, 35, 
0, 1, 2 

}

什么可能导致此问题？

原文

My Parallax mapping gives wrong results. I don't know what can be wrong.

alt text

alt text

The "shadow" is in the wrong place.

Light is pointing from the viewer and goes towards the cube.
Shader program (based on dhpoware.com):

[vert]
     varying vec3 lightDir;            
     varying vec3 viewDir;
     attribute vec4 tangent;
     void main() 
     { 
     gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
     gl_TexCoord[0] = gl_MultiTexCoord0;
     vec3 vertexPos = vec3(gl_ModelViewMatrix * gl_Vertex);
     vec3 n = normalize(gl_NormalMatrix * gl_Normal);
     vec3 t = normalize(gl_NormalMatrix * tangent.xyz);
     vec3 b = cross(n, t) * tangent.w;
     mat3 tbnMatrix = mat3(t.x, b.x, n.x,
                           t.y, b.y, n.y,
                           t.z, b.z, n.z);
     lightDir = (gl_LightSource[0].position.xyz - vertexPos) / 1000.0;
     lightDir = tbnMatrix * lightDir;
     viewDir = -vertexPos;
     viewDir = tbnMatrix * viewDir;
     } 

    [frag]
     varying vec3 lightDir;            
     varying vec3 viewDir;
     uniform sampler2D diffuseMap;
     uniform sampler2D normalMap;
     uniform sampler2D heightMap;
     uniform float scale;
     uniform float bias;
     void main() 
     { 
     vec3 v = normalize(viewDir);
     vec2 TexCoord = gl_TexCoord[0].st;
    {
     float height = texture2D(heightMap, gl_TexCoord[0].st).r;
     height = height * scale + bias;
     TexCoord = gl_TexCoord[0].st + (height * v.xy); 
    }
     vec3 l = lightDir;
     float atten = max(0.0, 1.0 - dot(l, l));
     l = normalize(l);
     vec3 n = normalize(texture2D(normalMap, TexCoord).rgb * 2.0 - 1.0);
     vec3 h = normalize(l + v);
     float nDotL = max(0.0, dot(n, l));
     float nDotH = max(0.0, dot(n, h));
     float power = (nDotL == 0.0) ? 0.0 : pow(nDotH, gl_FrontMaterial.shininess);
     vec4 ambient = gl_FrontLightProduct[0].ambient * atten;
     vec4 diffuse = gl_FrontLightProduct[0].diffuse * nDotL * atten;
     vec4 specular = gl_FrontLightProduct[0].specular * power * atten;
     vec4 color = gl_FrontLightModelProduct.sceneColor + ambient + diffuse + specular;color *= texture2D(diffuseMap,TexCoord);
     gl_FragColor = color ;
     }

log from cube content (tangents included, the fourth component is handedness):

------------------------------------------------------------------------------------------------------------------
VecContainer<Vertex> vertices = 

size: 36
space: 36
{
-4.000000, -4.000000, -4.000000, 
-4.000000, 4.000000, -4.000000, 
4.000000, 4.000000, -4.000000, 
4.000000, 4.000000, -4.000000, 
4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
4.000000, -4.000000, -4.000000, 
4.000000, -4.000000, 4.000000, 
4.000000, -4.000000, 4.000000, 
-4.000000, -4.000000, 4.000000, 
-4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
-4.000000, -4.000000, 4.000000, 
-4.000000, 4.000000, 4.000000, 
-4.000000, 4.000000, 4.000000, 
-4.000000, 4.000000, -4.000000, 
-4.000000, -4.000000, -4.000000, 
4.000000, -4.000000, -4.000000, 
4.000000, 4.000000, -4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, -4.000000, 4.000000, 
4.000000, -4.000000, -4.000000, 
-4.000000, 4.000000, -4.000000, 
-4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, -4.000000, 
-4.000000, 4.000000, -4.000000, 
-4.000000, -4.000000, 4.000000, 
4.000000, -4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
4.000000, 4.000000, 4.000000, 
-4.000000, 4.000000, 4.000000, 
-4.000000, -4.000000, 4.000000, 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<Vertex> texcoords = 

size: 36
space: 36
{
0.000000, 0.000000, 
0.000000, 1.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
1.000000, 0.000000, 
0.000000, 0.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 
1.000000, 0.000000, 
1.000000, 1.000000, 
1.000000, 1.000000, 
0.000000, 1.000000, 
0.000000, 0.000000, 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<Vertex> normals = 

size: 36
space: 36
{
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, -1.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
0.000000, -1.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
-1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
1.000000, 0.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 1.000000, 0.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 
0.000000, 0.000000, 1.000000, 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<tangent>* tangents = 

size: 36
space: 36
{
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, -0.000000, 0.000000, 1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, 1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
0.000000, 0.000000, -1.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, 0.000000, -1.000000, 
1.000000, 0.000000, -0.000000, -1.000000, 
1.000000, 0.000000, -0.000000, -1.000000, 
1.000000, 0.000000, -0.000000, -1.000000 

}

------------------------------------------------------------------------------------------------------------------
VecContainer<GLuint> indices = 

size: 12
space: 12
{
3, 4, 5, 
6, 7, 8, 
9, 10, 11, 
12, 13, 14, 
15, 16, 17, 
18, 19, 20, 
21, 22, 23, 
24, 25, 26, 
27, 28, 29, 
30, 31, 32, 
33, 34, 35, 
0, 1, 2 

}

What could cause this problem?

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评论（1）

酸甜透明夹心 2024-10-20 00:06:17

正如您之前的问题一样，我认为您仍然遇到同样的问题。您在某处忘记了减号，或者可能以错误的顺序执行了叉积。

As in your previous question, I think you still have the same issue. You forget a minus somewhere, or perhaps performed a cross product in the wrong order.

回复 原文
~没有更多了~

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