Question

我正在尝试创建一个Cocoa应用程序，该应用程序呈现一个包含某些模型的房间。

对于模型导入，我使用了JEFF LAMARCHE's WavefrontOBJScene class我修改过的使用OSX而不是iOS。

问题是，当我尝试渲染模型时，它们无法正确渲染。我无法找到解释为什么会发生这种情况。

[示例图片]

正如你所看到的那样，金字塔的内部面孔是可见的，即使立方体位于金字塔后面，它似乎也在前面。

绘图代码

- (BOOL) initGL
{
    test = !test;
    //glEnable(GL_CULL_FACE);
    //glCullFace(GL_BACK);
    glEnable( GL_TEXTURE_2D );                // Enable texture mapping
    glShadeModel( GL_SMOOTH );                // Enable smooth shading
    glClearColor( 0.0f, 0.0f, 0.0f, 0.5f );   // Black background
    glClearDepth( 1.0f );                     // Depth buffer setup
    glEnable( GL_DEPTH_TEST );                // Enable depth testing
    glDepthFunc( GL_LEQUAL );                 // Type of depth test to do
    glDepthRange(0,1);

    // Really nice perspective calculations
    glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
    glDisable(GL_BLEND);


    return !test;
}
- (void)drawRect:(NSRect)rect
{
    if (!test) [self initGL];

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glClearColor(0.1f, 0.1f, 0.1f, 1);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    [self setCamera];
    [self drawObjects];

    glFlush();
}

- (void)drawObjects
{
    glMatrixMode( GL_MODELVIEW );
    glPushMatrix();
    [self drawAnObject];
    glPopMatrix();

    glPushMatrix();
    [[objects objectAtIndex:0] openGLDraw];
    glPopMatrix();

    glPushMatrix();
    [[objects objectAtIndex:1] openGLDraw];
    glPopMatrix();

}

- (void)drawAnObject
{    
    glBegin(GL_QUADS);
    {
        for (int x = -256; x < 256; ++x) {
            for (int y = -256; y < 256; ++y) {
                glColor3f(colorR[256+x][256+y], colorG[256+x][256+y], colorB[256+x][256+y]);

                //glNormal3f(1.0, 1.0, 1.0);

                glVertex3f( x    , -1.0, y);
                glVertex3f( x+1.0, -1.0, y);
                glVertex3f( x+1.0, -1.0, y+1.0);
                glVertex3f( x    , -1.0, y+1.0);
            }
        }
    }
    glEnd();

    //glMatrixMode( GL_MODELVIEW );
    //glLoadIdentity();
}


- (void)setCamera
{    
    //SET
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    gluPerspective( 60, (float)(self.frame.size.width/self.frame.size.height), 0.1, 1000.0 );

    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();

    glRotatef( -cameraRotationY, 1.0f, 0.0f, 0.0f ); //ROT Y
    glRotatef( cameraRotationX, 0.0f, 1.0f, 0.0f ); //ROT X
    glTranslatef( -cameraPositionX, -cameraPositionY, cameraPositionZ ); // POS X Y Z
}

CSObject：

- (void)openGLDraw
{       
    glPushMatrix();
    //glLoadIdentity();


    //Set Origin
    glTranslatef( posX, posY, -posZ ); // POS X Y Z
    glRotatef( rotV, 1.0f, 0.0f, 0.0f ); //ROT Y
    glRotatef( rotH, 0.0f, 1.0f, 0.0f ); //ROT X

    glEnableClientState(GL_NORMAL_ARRAY);
    glEnableClientState(GL_VERTEX_ARRAY);

    //Draw objects
    for(CSGroup *group in groups) {        
        if(TRUE) {
            glShadeModel(GL_SMOOTH);
        } else {
            glShadeModel(GL_FLAT);
        }

        //VERTICES
        GLuint verticesName = [group verticesName:GL_STATIC_DRAW];
        glBindBuffer(GL_ARRAY_BUFFER, verticesName);
        glVertexPointer(3, GL_FLOAT, 0, 0);

        //NORMALS
        GLuint normalsName = [group normalsName:GL_STATIC_DRAW];
        glBindBuffer(GL_ARRAY_BUFFER, normalsName);
        glNormalPointer(GL_FLOAT, 0, 0);

        ColorRGBA color = group.material.ambientColor;
        glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, (GLfloat *)&color);
        color = group.material.diffuseColor;
        glColor4f(color.red, color.green, color.blue, color.alpha);
        glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, (GLfloat *)&color);
        color = group.material.specularColor;
        glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, (GLfloat *)&color);
        glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, group.material.shine);

        // load (if necessary) and bind the texture
        if(group.textureCoordinatesIndexData.length > 0) {
            glEnableClientState(GL_TEXTURE_COORD_ARRAY);
            GLuint textureCoordsName = [group textureCoordinatesName:GL_STATIC_DRAW];
            glEnable(GL_TEXTURE_2D);
            glBindBuffer(GL_ARRAY_BUFFER, textureCoordsName);
            glTexCoordPointer([group texCoordSize], GL_FLOAT, 0, 0);
            GLuint texId = [group.material.diffuseTexture textureName];
            glBindTexture(GL_TEXTURE_2D, texId);
        }

        GLuint indexesName = [group indexesName:GL_STATIC_DRAW];
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexesName);
        glDrawElements(GL_TRIANGLES, (GLsizei)group.indexCount, GL_UNSIGNED_SHORT, NULL);

        if(group.textureCoordinatesIndexData.length > 0) {
            glDisableClientState(GL_TEXTURE_COORD_ARRAY);
        }
    }

    glDisableClientState(GL_NORMAL_ARRAY);
    glDisableClientState(GL_VERTEX_ARRAY);

    glPopMatrix();
}

Answer 1

您的DEPTH_BITS返回零的事实意味着您没有深度缓冲区。因此，深度测试将始终通过，您将无法按深度排序。

我对Cocoa不太熟悉，但基本上你要做的就是在创建opengl上下文时，你必须要求创建一个深度缓冲区。（这将是您请求颜色位数的时候。）

我不知道究竟是什么命令控制这个cocoa，但如果你不知道（developer.apple.com - opengl_pixelformats），你可以在这里找到它。请注意这里提到的深度，并确保请求深度缓冲。

OpenGL绘图模型的顺序不正确

1 个答案: