正常的映射非常错误
Pil*_*pel 3 c++ opengl lighting glsl glm-math
我试图在我的opengl应用程序中实现常规映射,但我无法让它工作.
为了获得切线和bitangent(在其他地方称为binormals？)向量,我为网格中的每个三角形运行此函数:
void getTangent(const glm::vec3 &v0, const glm::vec3 &v1, const glm::vec3 &v2,
const glm::vec2 &uv0, const glm::vec2 &uv1, const glm::vec2 &uv2,
std::vector<glm::vec3> &vTangents, std::vector<glm::vec3> &vBiangents)
{
// Edges of the triangle : postion delta
glm::vec3 deltaPos1 = v1-v0;
glm::vec3 deltaPos2 = v2-v0;
// UV delta
glm::vec2 deltaUV1 = uv1-uv0;
glm::vec2 deltaUV2 = uv2-uv0;
float r = 1.0f / (deltaUV1.x * deltaUV2.y - deltaUV1.y * deltaUV2.x);
glm::vec3 tangent = (deltaPos1 * deltaUV2.y - deltaPos2 * deltaUV1.y)*r;
glm::vec3 bitangent = (deltaPos2 * deltaUV1.x - deltaPos1 * deltaUV2.x)*r;
for(int i = 0; i < 3; i++) {
vTangents.push_back(tangent);
vBiangents.push_back(bitangent);
}
}
之后,我调用glBufferData将顶点,法线,uvs,切线和bitangents上传到GPU.顶点着色器:
#version 430
uniform mat4 ProjectionMatrix;
uniform mat4 CameraMatrix;
uniform mat4 ModelMatrix;
in vec3 vertex;
in vec3 normal;
in vec2 uv;
in vec3 tangent;
in vec3 bitangent;
out vec2 fsCoords;
out vec3 fsVertex;
out mat3 TBNMatrix;
void main()
{
gl_Position = ProjectionMatrix * CameraMatrix * ModelMatrix * vec4(vertex, 1.0);
fsCoords = uv;
fsVertex = vertex;
TBNMatrix = mat3(tangent, bitangent, normal);
}
片段着色器:
#version 430
uniform sampler2D diffuseMap;
uniform sampler2D normalMap;
uniform mat4 ModelMatrix;
uniform vec3 CameraPosition;
uniform struct Light {
float ambient;
vec3 position;
} light;
uniform float shininess;
in vec2 fsCoords;
in vec3 fsVertex;
in mat3 TBNMatrix;
out vec4 color;
void main()
{
//base color
const vec3 brownColor = vec3(153.0 / 255.0, 102.0 / 255.0, 51.0 / 255.0);
color = vec4(brownColor * (texture(diffuseMap, fsCoords).rgb + 0.25), 1.0);//add a fixed base color (0.25), because its dark as hell
//general vars
vec3 normal = texture(normalMap, fsCoords).rgb * 2.0 - 1.0;
vec3 surfacePos = vec3(ModelMatrix * vec4(fsVertex, 1.0));
vec3 surfaceToLight = normalize(TBNMatrix * (light.position - surfacePos)); //unit vector
vec3 eyePos = TBNMatrix * CameraPosition;
//diffuse
float diffuse = max(0.0, dot(normal, surfaceToLight));
//specular
float specular;
vec3 incidentVector = -surfaceToLight; //unit
vec3 reflectionVector = reflect(incidentVector, normal); //unit vector
vec3 surfaceToCamera = normalize(eyePos - surfacePos); //unit vector
float cosAngle = max(0.0, dot(surfaceToCamera, reflectionVector));
if(diffuse > 0.0)
specular = pow(cosAngle, shininess);
//add lighting to the fragment color (no attenuation for now)
color.rgb *= light.ambient;
color.rgb += diffuse + specular;
}
我得到的图像完全不正确.(光线位于相机上)
我在这做错了什么？
我的赌注是碎片着色器中的颜色设置/混合......
您将输出颜色设置为一次以上
如果我在某些gfx驱动程序上正确记住这些问题,例如行后的所有问题
Run Code Online (Sandbox Code Playgroud)color = vec4(brownColor * (texture(diffuseMap, fsCoords).rgb + 0.25), 1.0);//add a fixed base color (0.25), because its dark as hell可以被司机删除......
你正在添加
color而intensities不是color*intensity但我可以忽略一些.
首先尝试正常/凹凸着色
忽略环境,反射,镜面......然后如果它工作,则逐个添加其余部分.始终检查着色器的编译日志
懒得进一步分析你的代码,所以我就是这样做的:
左侧大小是太空船对象(类似于ZXS Elite的Viper),具有固定功能.右侧相同(对象旋转稍有不同),GLSL着色器就位,这个正常/凹凸贴图
[顶点]
//------------------------------------------------------------------
#version 420 core
//------------------------------------------------------------------
// texture units:
// 0 - texture0 map 2D rgba
// 1 - texture1 map 2D rgba
// 2 - normal map 2D xyz
// 3 - specular map 2D i
// 4 - light map 2D rgb rgb
// 5 - enviroment/skybox cube map 3D rgb
uniform mat4x4 tm_l2g;
uniform mat4x4 tm_l2g_dir;
uniform mat4x4 tm_g2s;
uniform mat4x4 tm_l2s_per;
uniform mat4x4 tm_per;
layout(location=0) in vec3 pos;
layout(location=1) in vec4 col;
layout(location=2) in vec2 txr;
layout(location=3) in vec3 tan;
layout(location=4) in vec3 bin;
layout(location=5) in vec3 nor;
out smooth vec3 pixel_pos;
out smooth vec4 pixel_col;
out smooth vec2 pixel_txr;
//out flat mat3 pixel_TBN;
out smooth mat3 pixel_TBN;
//------------------------------------------------------------------
void main(void)
{
vec4 p;
p.xyz=pos;
p.w=1.0;
p=tm_l2g*p;
pixel_pos=p.xyz;
p=tm_g2s*p;
gl_Position=p;
pixel_col=col;
pixel_txr=txr;
p.xyz=tan.xyz; p.w=1.0; pixel_TBN[0]=normalize((tm_l2g_dir*p).xyz);
p.xyz=bin.xyz; p.w=1.0; pixel_TBN[1]=normalize((tm_l2g_dir*p).xyz);
p.xyz=nor.xyz; p.w=1.0; pixel_TBN[2]=normalize((tm_l2g_dir*p).xyz);
}
//------------------------------------------------------------------
[分段]
//------------------------------------------------------------------
#version 420 core
//------------------------------------------------------------------
in smooth vec3 pixel_pos;
in smooth vec4 pixel_col;
in smooth vec2 pixel_txr;
//in flat mat3 pixel_TBN;
in smooth mat3 pixel_TBN;
uniform sampler2D txr_texture0;
uniform sampler2D txr_texture1;
uniform sampler2D txr_normal;
uniform sampler2D txr_specular;
uniform sampler2D txr_light;
uniform samplerCube txr_skybox;
const int _lights=3;
uniform vec3 light_col0=vec3(0.1,0.1,0.1);
uniform vec3 light_dir[_lights]= // direction to local star in ellipsoid space
{
vec3(0.0,0.0,+1.0),
vec3(0.0,0.0,+1.0),
vec3(0.0,0.0,+1.0),
};
uniform vec3 light_col[_lights]= // local star color * visual intensity
{
vec3(1.0,0.0,0.0),
vec3(0.0,1.0,0.0),
vec3(0.0,0.0,1.0),
};
out layout(location=0) vec4 frag_col;
const vec4 v05=vec4(0.5,0.5,0.5,0.5);
const bool _blend=false;
const bool _reflect=true;
//------------------------------------------------------------------
void main(void)
{
float a=0.0,b,li;
vec4 col,blend0,blend1,specul,skybox;
vec3 normal;
col=(texture2D(txr_normal,pixel_txr.st)-v05)*2.0; // normal/bump maping
// normal=pixel_TBN*col.xyz;
normal=pixel_TBN[0];
blend0=texture(txr_texture0,pixel_txr.st);
blend1=texture(txr_texture1,pixel_txr.st);
specul=texture(txr_specular,pixel_txr.st);
skybox=texture(txr_skybox,normal);
if (_blend)
{
a=blend1.a;
blend0*=1.0-a;
blend1*=a;
blend0+=blend1;
blend0.a=a;
}
col.xyz=light_col0; col.a=0.0; li=0.0; // normal shading (aj s bump mapingom)
for (int i=0;i<_lights;i++)
{
b=dot(light_dir[i],normal.xyz);
if (b<0.0) b=0.0;
// b*=specul.r;
li+=b;
col.xyz+=light_col[i]*b;
}
col*=blend0;
if (li<=0.1)
{
blend0=texture2D(txr_light,pixel_txr.st);
blend0*=1.0-a;
blend0.a=a;
col+=blend0;
}
if (_reflect) col+=skybox*specul.r;
col*=pixel_col;
if (col.r<0.0) col.r=0.0;
if (col.g<0.0) col.g=0.0;
if (col.b<0.0) col.b=0.0;
a=0.0;
if (a<col.r) a=col.r;
if (a<col.g) a=col.g;
if (a<col.b) a=col.b;
if (a>1.0)
{
a=1.0/a;
col.r*=a;
col.g*=a;
col.b*=a;
}
frag_col=col;
}
//------------------------------------------------------------------
这些源代码有点陈旧,并且针对特定应用混合了不同的东西
因此,只从中提取您需要的东西.如果你对变量名称感到困惑,那么请评论我...
tm_代表变换矩阵l2g代表局部坐标系到全局坐标系变换dir意味着转换只改变方向(偏移量为0,0,0)g2s代表全球到屏幕......per是透视变换......
GLSL编译日志
在编辑着色器之后,你必须以编程方式获取其内容(不是应用!!!).我这样做是glGetShaderInfoLog为每个着色器调用函数,我使用的程序...
[笔记]
一些驱动程序优化"未使用"变量.正如您在图像中看到的那样,txr_texture1即使片段着色器在代码中有它,但在此App中没有使用混合,因此驱动程序也没有找到它,因此驱动程序自行删除它...
着色器日志可以显示很多(语法错误,警告......)
有很少的GLSL IDE可以让着色器变得简单,但我更喜欢自己的,因为我可以直接在其中使用目标应用程序代码.我看起来像这样:
每个txt窗口都是着色器源(顶点,片段,...),右下角是剪贴板,左上角是最后一次编译后的着色器日志,左下角是预览.我设法编写它像Borland风格的IDE(键也和语法高亮)其他IDE看起来相似(不同颜色的粗:))无论如何你想玩着色器下载这样的应用程序或自己做它会帮助很多......
TBN创建也可能存在问题
您应该通过在每个顶点位置绘制彩色线来直观地检查TBN矢量(正切,正常,法线)是否与物体表面相对应.只是为了确定...这样的事情:
