The simple model was only a mental concept Ive never tried using, except in rag-dolling.
And even then you have to use PH_BOX. 3DGS physics seriously sucks on collisions.

Eiieaglh... Really gone wrong with the move, in my best opinion. I cant even see why much of it is there?
This is all I see as being needed.
Code:
        vec_set(vAhead,  vector((key_cuu-key_cud)*75,0,0));   //feed keyboard into engine. 
        vec_rotate(vAhead, player.pan);                       //rotates by pan,tilt,roll ALL at the same time...
        phent_addvellocal(player,vAhead,NULLVECTOR);          // Now apply physics force in the directions it is facing....
But you should probably have a "phent_setmaxspeed" set on the player at physics setup time.
Also, you should 'probably' use phent_addforcelocal(player,vAhead,player.x); rather than
phent_addvellocal. I think it will give a smoother-looking acceleration.

Dont worry about the questions, its helping me kill a boring work-day.

Post2 ::

Yeah, ditch the c-move completely. And create the bullets/shells inside the tank at the breech.
BUT, I just remembered, be sure to use the PASSABLE flag on any entity during its physics setup.
eg
Code:
        set(me.PASSABLE);                    <<<<<<important
        phent_settype(me,PH_RIGID,PH_BOX);
	phent_setmass(me,0.012,PH_SPHERE);//45kg
	phent_setfriction(me,100);
	phent_setdamping(me,2,100);
	phent_setgroup(me,2);
        reset(me.PASSABLE);                  <<<<<<important

Otherwise collisions may be triggered (but not yet executed) BEFORE you get the
chance to phent_setgroup....

"There is no fate but what WE make." - CEO Cyberdyne Systems Corp.
A8.30.5 Commercial