0

我正在尝试使用我的着色器与 VAO 一起绘制来进行照明。但是,每当我加载 glNormalPointer 时,我的着色器都不会在对象上绘制,并且我在调试时遇到了麻烦。

这是我的代码的一部分:

        glEnableClientState(GL_VERTEX_ARRAY);
        glEnableClientState(GL_NORMAL_ARRAY);
        glVertexPointer(3, GL_FLOAT, 0, vertices);
        glNormalPointer(GL_FLOAT, 0, normals);
        glDrawElements(GL_QUADS, 400, GL_UNSIGNED_INT, indices);
        glDisableClientState(GL_VERTEX_ARRAY);
        glDisableClientState(GL_NORMAL_ARRAY);

它绘制正确,但没有正确进行照明。如果我注释掉用于正常工作的三行,那么程序将正确运行,这对我来说没有意义。法线只是表面的法线。它们应该是正确的,因为当我使用 glNormal3f() 和 glVertex3f() 加载它们时,对象呈现如下。着色器文件来自 lighthouse3d 网站,它们已正确渲染。

这是禁用 glNormalPointer() 的情况。

在此处输入图像描述

这是启用了 glNormalPointer 的情况,因为没有注释掉。

在此处输入图像描述

有什么我错过的吗?

这是着色器代码:这是我从 lighthouse3d 获得的顶点着色器

varying vec4 diffuse,ambientGlobal,ambient;
varying vec3 normal,lightDir,halfVector;
varying float dist;

void main()
{   
vec4 ecPos;
vec3 aux;

/* first transform the normal into eye space and normalize the result */
normal = normalize(gl_NormalMatrix * gl_Normal);

/* now normalize the light's direction. Note that according to the
OpenGL specification, the light is stored in eye space. Also since 
we're talking about a directional light, the position field is actually 
direction */
ecPos = gl_ModelViewMatrix * gl_Vertex;
aux = vec3(gl_LightSource[2].position-ecPos);
lightDir = normalize(aux);

/* compute the distance to the light source to a varying variable*/
dist = length(aux);

/* Normalize the halfVector to pass it to the fragment shader */
halfVector = normalize(gl_LightSource[2].halfVector.xyz);

/* Compute the diffuse, ambient and globalAmbient terms */
diffuse = gl_FrontMaterial.diffuse * gl_LightSource[2].diffuse;
ambient = gl_FrontMaterial.ambient * gl_LightSource[2].ambient;
ambientGlobal = gl_LightModel.ambient * gl_FrontMaterial.ambient;

gl_Position = ftransform();
 } 

这是我从 lighthouse3d 获得的片段着色器:

varying vec4 diffuse,ambientGlobal, ambient;
varying vec3 normal,lightDir,halfVector;
varying float dist;


void main()
{
vec3 n,halfV,viewV,ldir;
float NdotL,NdotHV;
vec4 color = ambientGlobal;
float att;

/* a fragment shader can't write a verying variable, hence we need
a new variable to store the normalized interpolated normal */
n = normalize(normal);

/* compute the dot product between normal and ldir */
NdotL = max(dot(n,normalize(lightDir)),0.0);

if (NdotL > 0.0) {

    att = 1.0 / (gl_LightSource[2].constantAttenuation +
            gl_LightSource[2].linearAttenuation * dist +
            gl_LightSource[2].quadraticAttenuation * dist * dist);
    color += att * (diffuse * NdotL + ambient);


    halfV = normalize(halfVector);
    NdotHV = max(dot(n,halfV),0.0);
    color += att * gl_FrontMaterial.specular * gl_LightSource[2].specular * pow(NdotHV,gl_FrontMaterial.shininess);
}

gl_FragColor = color;

}

我没有写任何这些,只是想让它们与我的代码一起工作。

4

0 回答 0