How do I use local Movement?[solved]

[trollger]

I Don't know how to use local Movement in irrlicht.
can anyone help me?

[terier]

get position, increment, set position.

[trollger]

Thanks but I mean lets say I have a cube that is controlled with the WASD keys and it turns left and right depending on the mouses position. The problem I have right now is when I rotate the cube and then move it forward it does not move toward the new direction it continues to move toward its absolute XY and Z not local

[terier]

Have you ever heard of trigonometric functions?
You probably need something like this:

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vector3df pos = node->getPosition();
f32 rot = node->getRotation().Y;
f32 distance = 10.f; //or speed, if you'd like to put it that way

pos.X += cos(rot * DEGTORAD) * distance;
pos.Z += sin(rot * DEGTORAD) * distance;

node->setPosition(pos);

[lazerblade]

Three functions which you should copy and use,


For translation:

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/*

  ==========

    translateNodeLoc -- translate a scene node locally

  ==========

*/

void translateNodeLoc(ISceneNode *node, vector3df amt)

{

    irr::core::matrix4 m;

    m.setRotationDegrees(node->getRotation());

    m.transformVect(amt);

    node->setPosition(node->getPosition() + vel);

    node->updateAbsolutePosition();

}

Example:

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translateNodeLoc(mySceneNode, vector3df(0,0,1));

Will move the node +1 on it's local Z axis.



For rotation:

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/*

  ==========

    getMatrixRotation -- gets the real rotation of a matrix

  ==========

 */

vector3df getMatrixRotation(const matrix4& mx)

{

   core::vector3df r;

   r.X = asinf(-mx(2,1));

   const f32 t = cosf(r.X);

   if (.001f < t) {

      r.Z = atan2f(mx(0,1), mx(1,1));

      r.Y = atan2f(mx(2,0), mx(2,2));

   }

   else {

      r.Z = atan2f(-mx (1,0), mx (0,0));

      r.Y = 0.f;

   }

   return (r * (180/PI));

}


/*

  ==========

    rotateNodeLoc -- rotate a scene node locally
  ==========

*/

void rotateNodeLoc(irr::scene::ISceneNode *node, irr::core::vector3df rot)

{

    irr::core::matrix4 m;

    m.setRotationDegrees(node->getRotation());



    irr::core::matrix4 n;

    n.setRotationDegrees(rot);



    m *= n;



    node->setRotation( getMatrixRotation(m) );

    node->updateAbsolutePosition();

}

Example:

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rotateNodeLoc(mySceneNode, vector3df(1,0,0));

Will rotate the node +1 along it's local X axis.


Hope that helps.

[trollger]

awesome thanks

[Acki]

Three functions which you should copy and use

hmm, I had a quick look at the functions and I wonder how this one works:

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void translateNodeLoc(ISceneNode *node, vector3df amt)

{

    irr::core::matrix4 m;

    m.setRotationDegrees(node->getRotation());

    m.transformVect(amt);

    node->setPosition(node->getPosition() + vel);

    node->updateAbsolutePosition();

}

I mean what do you use the matrix for (I see not using it) and how is vel defined ???

[Lonesome Ducky]

Acki, I think he may have meant to put amt instead of vel, that would make much more sense.

[Acki]

Acki, I think he may have meant to put amt instead of vel, that would make much more sense.

my guess was that vel is the speed (velocity) and has to be multiplied by amt...

[lazerblade]

Oops... I think I made a mistake when I copied it over...

This is what that function was supposed to be:

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/*

  ==========

    translateNodeLoc -- translate a scene node locally

  ==========

*/

void translateNodeLoc(ISceneNode *node, vector3df amt)

{

    irr::core::matrix4 m;

    m.setRotationDegrees(node->getRotation());

    m.transformVect(amt);

    node->setPosition(node->getPosition() + amt);

    node->updateAbsolutePosition();

}

[Lonesome Ducky]

YES! I WIN! HAHAHAHA!

[Acki]

YES! I WIN! HAHAHAHA!