当我在我的计算机上运行该程序时，它完全按照我的预期工作。但是，当我尝试在我的校园实验室计算机上运行它时，片段着色器是各种奇怪的。
现在它只是一个简单的 Phong 光照计算，在原点有一个点光源。然而，在实验室计算机上，它看起来更像是 cel shading 和手电筒之间的某种奇怪的结合。我运行 ATI 显卡，而实验室计算机运行 NVIDIA。阴影在 Mac 上也按预期工作（不知道显卡）。
NVIDIA 卡最高支持 OpenGL 3.1，尽管我在这个 Linux 发行版上以 2.1 运行它。我已经尝试将着色器版本限制为 1.2 (GLSL)，以及许多其他内容，但它们获得了相同的结果。最奇怪的是，当我进行顶点着色而不是像素着色时，两台计算机上的结果都是一样的……我已经用尽了关于如何解决这个问题的想法。
这是顶点着色器：
#version 120
attribute vec2 aTexCoord;
attribute vec3 aPosition;
attribute vec3 aNormal;
attribute vec3 camLoc;
attribute float mat;
varying vec3 vColor;
varying vec2 vTexCoord;
varying vec3 normals;
varying vec3 lightPos;
varying vec3 camPos;
varying float material;
uniform mat4 uProjMatrix;
uniform mat4 uViewMatrix;
uniform mat4 uModelMatrix;
uniform mat4 uNormMatrix;
uniform vec3 uLight;
uniform vec3 uColor;
void main()
{
//set up object position in world space
vec4 vPosition = uModelMatrix * vec4(aPosition, 1.0);
vPosition = uViewMatrix * vPosition;
vPosition = uProjMatrix * vPosition;
gl_Position = vPosition;
//set up light vector in world space
vec4 vLight = vec4(uLight, 1.0) * uViewMatrix;
lightPos = vLight.xyz - vPosition.xyz;
//set up normal vector in world space
normals = (vec4(aNormal,1.0) * uNormMatrix).xyz;
//set up view vector in world space
camPos = camLoc.xyz - vPosition.xyz;
//set up material shininess
material = mat;
//pass color and vertex
vColor = uColor;
vTexCoord = aTexCoord;
}
和片段着色器：
#version 120
varying vec3 lightPos;
varying vec3 normals;
varying vec3 camPos;
varying vec2 vTexCoord;
varying vec3 vColor;
varying float material;
uniform sampler2D uTexUnit;
uniform mat4 uProjMatrix;
uniform mat4 uViewMatrix;
uniform mat4 uModelMatrix;
void main(void)
{
float diffuse;
float diffuseRed, diffuseBlue, diffuseGreen;
float specular;
float specRed, specBlue, specGreen;
vec3 lightColor = vec3(0.996, 0.412, 0.706); //color of light (HOT PINK) **UPDATE WHEN CHANGED**
vec4 L; //light vector
vec4 N; //normal vector
vec4 V; //view vector
vec4 R; //reflection vector
vec4 H; //halfway vector
float red;
float green;
float blue;
vec4 texColor1 = texture2D(uTexUnit, vTexCoord);
//diffuse calculations
L = vec4(normalize(lightPos),0.0);
N = vec4(normalize(normals),0.0);
N = uModelMatrix * N;
//calculate RGB of diffuse light
diffuse = max(dot(N,L),0.0);
diffuseRed = diffuse*lightColor[0];
diffuseBlue = diffuse*lightColor[1];
diffuseGreen = diffuse*lightColor[2];
//specular calculations
V = vec4(normalize(camPos),0.0);
V = uModelMatrix * V;
R = vec4(-1.0 * L.x, -1.0 * L.y, -1.0 * L.z, 0.0);
float temp = 2.0*dot(L,N);
vec3 tempR = vec3(temp * N.x, temp * N.y, temp * N.z);
R = vec4(R.x + tempR.x, R.y + tempR.y, R.z + tempR.z, 0.0);
R = normalize(R);
H = normalize(L + V);
specular = dot(H,R);
specular = pow(specular,material);
specRed = specular*lightColor[0];
specBlue = specular*lightColor[1];
specGreen = specular*lightColor[2];
//set new colors
//textures
red = texColor1[0]*diffuseRed + texColor1[0]*specRed*0.7 + texColor1[0]*.05;
green = texColor1[1]*diffuseBlue + texColor1[1]*specBlue*0.7 + texColor1[1]*.05;
blue = texColor1[2]*diffuseGreen + texColor1[2]*specGreen*0.7 + texColor1[2]*.05;
//colors
red = vColor[0]*diffuseRed + vColor[0]*specRed*0.7 + vColor[0]*.05;
green = vColor[1]*diffuseBlue + vColor[1]*specBlue*0.7 + vColor[1]*.05;
blue = vColor[2]*diffuseGreen + vColor[2]*specGreen*0.7 + vColor[2]*.05;
gl_FragColor = vec4(red, green, blue, 1.0);
}