# Problem with move

1. So I have a 3d plane and terrain. It’s flight forward. The plane is armed with 2 bombs.

2. I shoot bomb, it faster than plane.

3. The problem is when I want move my plane. The bomb is moving with plane

4. I want that bomb move independent after shoot, how can I make it?

I’m beginer in OpenGL I’ve tired with glPushMatrix and glPopMatrix but it doesn’t work. Anyone can help me?

The code:

``````
void renderScene(void) {
hMap.DrawHeightMap(); // Draw terrain

glPushMatrix();
glTranslatef(xo,yo,zo);  // Plane's position
glRotatef(graus, 1.0, 0.0, 0.0); //Change plane position
glRotatef(grausz, 0.0, 0.0, 1.0);

plane->draw(); // Draw plane

// Bombs, connect it to "plane position"
glPushMatrix();
glTranslatef(-0.35f,-0.22f,bomb1air+(-0.5f));
bomb1->draw();
glTranslatef(0.70f,0.0f,bomb2air+(0.0f-bomb1air));
bomb2->draw();
glTranslatef(-0.35f,0.22f,(0.5f-(bomb1air+bomb2air)));
glPopMatrix();

glPopMatrix();
glFlush();
}

``````

When I click shoot, I’m changing bomb1air/bomb2air position+0.01 so it moves faster than plane (in the glutIdleFunc() function).

I’ve made an image to show you what i mean but unfortunetly I can’t post any links.

You are pushing the matrix but not resetting before you draw your bomb.

You logic should be

push matrix
set matrix to a know value (usually the identity)
modify matrix
draw obj
pop matrix

do the same thing for the next obj

Everything works fine (bombs are connected under wings and move with plane) until I shoot bomb. Its fly away from the plane. I want turn left the plane and bomb which I’ve shooted also turn left.

I’ve tired something like that:

``````
void renderScene(void) {

//Camera
gluLookAt(camx+xo, camy+yo,	camz+zo
xo,	yo,	zo,
0.0f, 1.0f,	0.0f);

hMap.DrawHeightMap(); // Draw terrain

glPushMatrix();
glTranslatef(xo,yo,zo);  // Plane's position
glRotatef(graus, 1.0, 0.0, 0.0); //Change plane position
glRotatef(grausz, 0.0, 0.0, 1.0);
plane->draw(); // Draw plane
glPopMatrix();

// Bombs, connect it to "plane position"
glPushMatrix();
glTranslatef(xo,yo,zo);  // Plane's position (connect it under wing)
glTranslatef(-0.35f,-0.22f,bomb1air+(-0.5f));
bomb1->draw();
glTranslatef(0.70f,0.0f,bomb2air+(0.0f-bomb1air));
bomb2->draw();
glTranslatef(-0.35f,0.22f,(0.5f-(bomb1air+bomb2air)));
glPopMatrix();

glFlush();
}

``````

But I don’t even see the bombs now.

Btw. I’ve also camera connected with plane (camera is placed behind airplane)

Edit:
It works! Problem was with the camera setting, thanks tonyo_au!