Orientation vector

[koocake]

Hi there,

I want to know how I can get the vector which points in the direction that an object is pointing, so that
I can apply a force in that direction.

I have tried :
car->GetTransform()*CS_VEC_FORWARD;

and
car->GetOrientation()*CS_VEC_FORWARD;

and
car->GetTransform().Other2This(CS_VEC_FORWARD);

but none of these seem to work, the force seems to be applied along the world axes, not in the direction that the car faces!

can you help?

regards, Kate Mallichan

[jorrit]

Hi there,

I want to know how I can get the vector which points in the direction that an object is pointing, so that
I can apply a force in that direction.

I have tried :
car->GetTransform()*CS_VEC_FORWARD;

and
car->GetOrientation()*CS_VEC_FORWARD;

and
car->GetTransform().Other2This(CS_VEC_FORWARD);

but none of these seem to work, the force seems to be applied along the world axes, not in the direction that the car faces!

can you help?

regards, Kate Mallichan

I need to see a bit more code. How exactly are you using that vector?

Greetings,

[koocake]

I am applying the force as follows:

car->AddForce(vector*force);

I have also tried car->AddRelForce(vector*force);

but the car either moves in funny directions, or towards the axes.

regards, Kate

[jorrit]

The functions AddForce() is in world space and AddRelForce() is in local space. So AddRelForce() should work. What do you mean by 'funny' directions? Also perhaps show me the exact code you're using.

Greetings,

[koocake]

I am using the following code:

    car->AddRelForce(CS_VEC_FORWARD*acceleration_force);
    car->Update();

The problem is that the force seems to be applied along the nearest world axis, so that the car veers towards the axes
when it is supposed to be moving forwards in the direction is is pointing. I think I may have to do something with car->GetOrientation() but I am not sure what. I would appreciate any help you can give as this is becoming an urgent situation with a project deadline coming up!

thankyou for your help,

Kate Mallichan

[jorrit]

How is the force vector calculated? I don't have sufficient information to really know what is going on here.

Greetings,

[koocake]

the force is simply an int value, not a vector. is this where i am going wrong?

[jorrit]

the force is simply an int value, not a vector. is this where i am going wrong?

Hmm... Perhaps you should at least make it a float. An int sounds a bit weird. Otherwise I have no clue without seeing more code.

Greetings,

[Lak Moore]

Is this what you are after?

Code:

    csVector3 currPos;
    float yRot;
    iSector* sector;
   
    csRef<iPcLinearMovement> lm = celQueryPropertyClassEntity<iPcLinearMovement> (entity);

    lm->GetLastPosition(current, yRot, sector);
    csVector3 delta(0);

    theta = yRot + PI;
    cosTH = cos(theta);
    sinTH = sin(theta);
    //rotate delta by yRot
    delta.x = cosTH + sinTH;
    delta.z = -sinTH + cosTH;
    delta = delta.Unit() * FORCE   //FORCE is your force and it can be an int if you want