Question

我正在使用通用OpenGL游戏项目，它自动创建2个旋转立方体。我试图找出如何将每个面/顶点更改为不同的颜色。目前，它只允许您更改整个多维数据集的颜色。

Answer 1

将颜色值添加到完整数据

GLfloat gCubeVertexData[324] = 
{
    // Data layout for each line below is:
    // positionX, positionY, positionZ,     normalX, normalY, normalZ,  your color
    0.5f, -0.5f, -0.5f,        1.0f, 0.0f, 0.0f,        1.0, 1.0, 0.5,
    0.5f, 0.5f, -0.5f,         1.0f, 0.0f, 0.0f,        1.0, 0.5, 0.5,
....
};

在setupGL更新为：

    glEnableVertexAttribArray(GLKVertexAttribPosition);
    glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 36, BUFFER_OFFSET(0));
    glEnableVertexAttribArray(GLKVertexAttribNormal);
    glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 36, BUFFER_OFFSET(12));
    glEnableVertexAttribArray(GLKVertexAttribColor);
    glVertexAttribPointer(GLKVertexAttribColor, 3, GL_FLOAT, GL_FALSE, 36, BUFFER_OFFSET(24));

找到字符串glBindAttribLocation(_program, GLKVertexAttribNormal, "normal"); 并添加：

glBindAttribLocation(_program, GLKVertexAttribColor, "color");

和Shader.vsh：

attribute vec4 position;
attribute vec3 normal;
attribute vec4 color;

varying lowp vec4 colorVarying;

uniform mat4 modelViewProjectionMatrix;
uniform mat3 normalMatrix;

void main()
{
    vec3 eyeNormal = normalize(normalMatrix * normal);
    vec3 lightPosition = vec3(0.0, 0.0, 1.0);
    vec4 diffuseColor = vec4(0.4, 0.4, 1.0, 1.0);

    float nDotVP = max(0.0, dot(eyeNormal, normalize(lightPosition)));

    colorVarying = color;// * diffuseColor * nDotVP;

    gl_Position = modelViewProjectionMatrix * position;
}

但是如果你明白为什么需要做那些操作会更好！

改变每个面/顶点的颜色？ OpenGL游戏项目

1 个答案: