当前位置： 文江博客话题详情

GLSL、Opengl 中的视差贴图问题

发布于 2024-10-13 00:06:17 字数 7951 浏览 5 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?

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

扫码二维码加入Web技术交流群

发布评论

需要 登录 才能够评论， 你可以免费 注册 一个本站的账号。

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~

关于作者

独留℉清风醉

暂无简介

0 文章
0 评论
24 人气
发私信

相关话题

更多

热门标签

操作系统 程序设计 IT运维 Linux系统管理 JavaScript 服务器应用 solaris C/C++ PHP Shell BSD Vue.js aix Oracle Python HTML 系统管理 HTML5 CSS 前端
更多

推荐作者

胡图图

文章 0 评论 0

zt006

文章 0 评论 0

z祗昰~

文章 0 评论 0

冰葑

文章 0 评论 0

野の

文章 0 评论 0

天空

文章 0 评论 0

更多

友情链接

文江博客
    我们使用 Cookies 和其他技术来定制您的体验包括您的登录状态等。通过阅读我们的 隐私政策 了解更多相关信息。 单击 接受 或继续使用网站，即表示您同意使用 Cookies 和您的相关数据。
    原文