如何使用 glRotatef 围绕对象的局部(非全局)轴执行旋转?

How do I perform rotations about an object's local (not global) axes using glRotatef?

本文关键字:全局 执行 旋转 局部 glRotatef 何使用 对象      更新时间:2023-10-16

我有一个网格/游戏对象旋转与glRotatef,使用FreeGLUT库:

glPushMatrix();
    glTranslatef(GlobalPos_x, GlobalPos_y, GlobalPos_z);
    glRotatef(Global_Yaw,0,1,0);
    glRotatef(Global_Pitch,1,0,0);
    glRotatef(Global_Roll,0,0,1);
    RenderMesh(mesh_Plane);
glPopMatrix();

开始时,对象与正向z轴对齐;y轴向上,x轴向左


"控制":

W:每帧俯仰+5度

S:每帧距-5度

A:每帧偏航+5度

D:每帧偏航-5度


目标:Global_Yaw, Global_Pitch和Global_Roll值必须以某种方式从这些控件(范围分别为-180到+180,-90到+90和-180到+180)递增。

问题是,如果飞机已经倾斜了90度它原来的位置,"偏航"会使它旋转y轴(万向节锁定),这应该只发生在第一人称射击。

所以简单地做'if(GetAsyncKeyState(Key_A)) Global_Yaw += 5;'不是我想要的。


编辑:Square 2

根据tkausl的提醒,我翻出了我早期的一个尝试。我的想法是,我将飞机当前的全局角度转换成一个矩阵,将这个矩阵与玩家按键输入生成的另一个矩阵相乘,然后以某种方式使用这个矩阵获得新的Global_Yaw, Global_Pitch和Global_Roll值:

// Convert ORIENTATION to MATRIX
Omatrix00 = cos(Global_Pitch)*cos(Global_Yaw);
Omatrix01 = sin(Global_Pitch);
Omatrix02 = cos(Global_Pitch)*sin(Global_Yaw);
Omatrix03 = 0;
Omatrix10 = -cos(Global_Roll)*sin(Global_Pitch)*cos(Global_Yaw)+sin(Global_Roll)*sin(Global_Yaw);
Omatrix11 = cos(Global_Roll)*cos(Global_Pitch);
Omatrix12 = -cos(Global_Roll)*sin(Global_Pitch)*sin(Global_Yaw)-sin(Global_Roll)*cos(Global_Yaw);
Omatrix13 = 0;
Omatrix20 = -sin(Global_Roll)*sin(Global_Pitch)*cos(Global_Yaw)-cos(Global_Roll)*sin(Global_Yaw);
Omatrix21 = sin(Global_Roll)*cos(Global_Pitch);
Omatrix22 = cos(Global_Roll)*cos(Global_Yaw)-sin(Global_Roll)*sin(Global_Pitch)*sin(Global_Yaw);
Omatrix23 = 0;
Omatrix30 = 0;
Omatrix31 = 0;
Omatrix32 = 0;
Omatrix33 = 1;

// Convert Commanded Turn Angles to MATRIX
matrix00 = cos(pitch_speed)*cos(yaw_speed);
matrix02 = cos(pitch_speed)*sin(yaw_speed);
matrix01 = sin(pitch_speed);
matrix03 = 0;
matrix10 = -cos(roll_speed)*sin(pitch_speed)*cos(yaw_speed)+sin(roll_speed)*sin(yaw_speed);
matrix11 = cos(roll_speed)*cos(pitch_speed);
matrix12 = -cos(roll_speed)*sin(pitch_speed)*sin(yaw_speed)-sin(roll_speed)*cos(yaw_speed);
matrix13 = 0;
matrix20 = -sin(roll_speed)*sin(pitch_speed)*cos(yaw_speed)-cos(roll_speed)*sin(yaw_speed);
matrix21 = sin(roll_speed)*cos(pitch_speed);
matrix22 = cos(roll_speed)*cos(yaw_speed)-sin(roll_speed)*sin(pitch_speed)*sin(yaw_speed);
matrix23 = 0;
matrix30 = 0;
matrix31 = 0;
matrix32 = 0;
matrix33 = 1;
// Next step: Somehow using this matrix to get new Global_Yaw, Global_Pitch and Global_Roll values...

我甚至不确定我在代码中是否正确地乘以了我的矩阵

你必须先绕x轴或z轴旋转,然后再绕y轴旋转才能得到正确的结果。在大多数类型的游戏中,你不需要滚动,你可以围绕x旋转,然后围绕z旋转,所有东西都按照预期旋转。