Parallax mapping issue in GLSL，Opengl [英] Parallax mapping issue in GLSL, Opengl
本文介绍了Parallax mapping issue in GLSL，Opengl的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的视差映射给出错误的结果。我不知道可能出错。
My Parallax mapping gives wrong results. I don't know what can be wrong.
阴影位置错误。
去向立方体。
着色器程序（基于dhpoware.com）：
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 ;
}
从多维数据集内容中记录日志（包括切线，第四个分量是手性） / p>
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
}
可能导致此问题的原因是什么？
What could cause this problem?
推荐答案
如你在上一个问题，我认为你仍然有同样的问题。你忘记了某处的某个地方，或者按错误的顺序执行了一个交叉乘积。
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.
这篇关于Parallax mapping issue in GLSL，Opengl的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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