使用程序生成创建磁盘但纹理无法正常工作

Question

期望的结果是整个磁盘的纹理几乎相同，但它似乎只在边缘周围的几个三角形区域正确渲染

disk.cpp

void disk::disk(int sides)
{
    float interval = ( 2 * PI )/sides;
    float angle = 0.0f;
    groundtexture = SOIL_load_OGL_texture

    (
        "gfx/ground.png", 
        SOIL_LOAD_AUTO,
        SOIL_CREATE_NEW_ID,
        SOIL_FLAG_MIPMAPS | SOIL_FLAG_NTSC_SAFE_RGB | SOIL_FLAG_COMPRESS_TO_DXT
    );
    glBegin(GL_TRIANGLES);
    for (int i = 0; i < sides; i++)
    {
        glBindTexture(GL_TEXTURE_2D,groundtexture);
        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
        glTexCoord2f(0.5, -0.5);
        glVertex3f(0, 0, 0);

        glTexCoord2f(cos(angle) / 2 + 0.5, - (sin(angle) / 2 + 0.5));
        glVertex3f(cos(angle), sin(angle), 0);

        glTexCoord2f(cos(angle + interval) / 2 + 0.5, -(sin(angle + interval) / 2 - 0.5));
        glVertex3f(cos(angle + interval), sin(angle + interval), 0);

        angle += interval;
    }
    glVertex3f(cos(0), sin(0), 0);
    glEnd();
    }

磁盘可以渲染，但纹理渲染不正确。编辑建议磁盘纹理不正确

Answer 1

GL_TEXTURE_MAG_FILTERcannot beGL_LINEAR_MIPMAP_LINEAR。它应该是 GL_LINEAR 而不是。所以替换这一行：

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_LINEAR);

和

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

Answer 2

无论如何，您都会遇到 OpenGL 错误。 glBindTexture、glTexParameteri 分别在 glBegin/glEnd 序列中不允许 glTexEnvf。只允许修改属性或指定顶点的指令。
绑定贴图，设置贴图参数前glBegin：

glBindTexture(GL_TEXTURE_2D, myTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

glBegin(GL_TRIANGLES);
for (int i = 0; i < sides; i++)
{
    glTexCoord2f(0.5, -0.5);
    glVertex3f(0, 0, 0);

    glTexCoord2f(cos(angle) / 2 + 0.5, - (sin(angle) / 2 + 0.5));
    glVertex3f(cos(angle), sin(angle), 0);

    glTexCoord2f(cos(angle + interval) / 2 + 0.5, -(sin(angle + interval) / 2 - 0.5));
    glVertex3f(cos(angle + interval), sin(angle + interval), 0);

    angle += interval;
}
glEnd();

Answer 3

GL_MODULATE 是整数值，而不是浮点值。如果你想要正确的结果，请使用正确的方法;)

glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

使用程序生成创建磁盘但纹理无法正常工作

using procedural generation to creat a disk but the texture does not work properly

c++

opengl

procedural-generation