《基于MFC的OpenGL编程》Part 5 Transformations - Rotations, Translations and Scaling

最新推荐文章于 2020-11-04 11:30:29 发布

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最新推荐文章于 2020-11-04 11:30:29 发布

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本文介绍了一个使用OpenGL实现的三维场景，其中包含了太阳、绕太阳旋转的行星以及该行星的卫星。通过变换（平移、旋转和缩放），演示了天体之间的相对运动，并介绍了如何通过代码来实现这一过程。

Transformations - Translation, Rotation and Scaling

Translation is nothing but moving along an arbitrary axis. Rotation is spinning about an arbitrary axis. Scaling is increase or decrease in size along an arbitrary axis. One important point to remember is that OpenGL uses a right hand coordinate system where Z-ve goes into the Screen. An object said to be undergoing a transformation could be undergoing a translation, rotation and/or scaling. Understanding how different types of transformations work together is very important.

本文将对地球进行建模，让其围绕着太阳，此外它还会有月球伴随,而在下文中将会加入对鼠标和键盘的事件响应机制。

绘制代码

void CCY457OpenGLView::RenderScene ()
{//绘制函数
        //Draw Sun
    glTranslatef(0.0f,0.0f,-5.0f);
    glRotatef(6,1.0f,0.0f,0.0f);
    glutWireSphere(1.0f,20,20);
    //Draw Planet
    glPushMatrix();
        glTranslatef(-1.2f,-0.5f,-2.0f);
        glRotatef(6,1.0f,0.0f,0.0f);
        glutWireSphere(0.5f,20,20);
        //Draw Moon
        glPushMatrix();
            glTranslatef(-1.2f,-0.5f,-2.0f);
            glRotatef(6,1.0f,0.0f,0.0f);
            glutWireSphere(0.05f,20,20);
        glPopMatrix();
    glPopMatrix();
}