How to get direction vector

[siny]

Hi.

I have this situation:



and I dont know how to get direction vector (marked on red). I need it to show Newton dynamics the direction in which the cannonball will fly.

Thanks for help

[hybrid]

Should be sceneNode.getRotation(), maybe needs to be normalized. If you have a parent scene node attached to it you have to get the AbsoluteTransformation.getRotation() which is in Euler angles, though.

[vi-wer]

I had the same problem with a character model.

I've created a frontDirection vector that shows the initial rotation and rotated it with the SceneNode.

If the getRotation() method doesn't work you could try this:
Create an empty SceneNode. Set position as initial direction (direction of your meshSceneNode):

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x=1,y=0,z=0 => direction vector showing along +X-axis.

Set that empty node as child of your meshSceneNode. If the meshSceneNode is rotated, the empty node is rotated too.

You can get the direction vector like this:

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vector3df dir = emptyNode->getAbsolutePosition() - meshNode->getAbsolutPosition();
dir.normalize();

not sure if it works.

[siny]

Thanks. that idea with empty node works perfectly.

[TheGameMaker]

uhm.. why simple if its possible to do it the hard way??

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vector3df dir(1,0,0);
node->getAbsoluteTransformation().rotateVect(dir);

(dunno if everything is spelled correct.. so if it doesn´t work, just havge a look for the correct spelling).