[Solved] Rotating scenenode issues

[kubatp]

Hi,
I really hope that someone will help me with this, because I simply cannot figure it out and it is getting a bit desperate

I am trying to develop bird's flight.
I use SceneNode.Yaw to rotate the bird around Y axis

yaw.png

I use SceneNode.Pitch to rotate the bird around X axis

pitch.png

I use SceneNode.Roll to rotate the bird around Z axis

roll.png

I should point out that I am using degrees when dealing with the rotations, the most important rotations around Y should work like this



I should also point out that I am using my own method for rotation

Code: Select all

public static void Rotate(this SceneNode node, Vector3 rotationVector)
{
	if (rotationVector.x != 0)
	{
		node.Pitch(new Degree(rotationVector.x).ValueRadians, Node.TransformSpace.TS_LOCAL);
	}

	if (rotationVector.y != 0)
	{
		node.Yaw(new Degree(rotationVector.y).ValueRadians, Node.TransformSpace.TS_PARENT);
	}

	if (rotationVector.z != 0)
	{
		node.Roll(new Degree(rotationVector.z).ValueRadians, Node.TransformSpace.TS_LOCAL);
	}
}

What I want to achieve is to pass to the Rotate method the vector of rotations, which would independently roll, pitch and yaw the bird.

Unfortunately there are few issues I am having with the rotations:

1. It seems like roll, pitch and yaw somehow relate to each other. When I call Yaw with specific number and the other two (pitch and roll) are both 0, it works fine. Once they (pitch or roll) are changed it doesnt correctly yaw the scenenode.
2. Is there a way how to get the rotation on Y axis? I thought that this would - sceneNode.Orientation.Yaw.ValueDegrees - is it, but it doesnt work correctly. For example, when there are no changes in pitch and roll, current rotation on Yaw is 29 degrees and I call Rotate function with 152 degrees in Y, it should return -179 degrees, but it returns -1. Why?
3. What should I do to get the functionality that whatever the pitch and roll is, when I call Rotate(0,30,0) it will change the rotation on Y axis about 30 degrees?

Thank you very much for your help. I was really trying to find an answer in other threads but without luck :-/

[frostbyte]

just improvising an answer( i did'nt mess much with this helper function )
1) maybe try NODE->_update() after doing any transform( e.g yaw, update, pitch update,roll update)
2)why do you use TS_PARENT on y-axis while TS_LOCAL on x,z axis? they should be all the same, no?
3)29+152=?( hint...its not 179 )

[kubatp]

Hi Frostbyte, thank you for the answer.

1) maybe try NODE->_update() after doing any transform( e.g yaw, update, pitch update,roll update)

I am using Mogre (Ogre 1.7.4), so there is no need to call update functions.

2)why do you use TS_PARENT on y-axis while TS_LOCAL on x,z axis? they should be all the same, no?

When I use TS_PARENT for pitch and roll the bird doesnt do the rotations I described in pictures.

3)29+152=?( hint...its not 179 )

Yes, that is the point. It is 181, which is -179, but it returns -1

[kubatp]

What I need is basically this http://www.ogre3d.org/forums/viewtopic.php?f=2&t=77710 but for all three axis together (not just for Y rotation)

[kubatp]

Maybe one more thing to add to explain, what I mean by independent rotations.
I need to find a way how to call this:

Code: Select all

Rotate(new Vector(0,45,0));
Rotate(new Vector(0,0,45));
Rotate(new Vector(45,0,0));

Rotate(new Vector(0,-45,0));
Rotate(new Vector(-45,0,0));
Rotate(new Vector(0,0,-45));

and get the same orientation as there was at the beginning. Please notice different order of the vectors.

[Zonder]

This should make things easier for you http://www.ogre3d.org/tikiwiki/Euler+Angle+Class

[kubatp]

This should make things easier for you http://www.ogre3d.org/tikiwiki/Euler+Angle+Class

Zonder, thank you very much!
This is exactly what I needed.

[Kojack]

Your code looks like c#, in which case there's http://www.ogre3d.org/tikiwiki/tiki-ind ... lass+Mogre
It's a c# version of the http://www.ogre3d.org/tikiwiki/Euler+Angle+Class c++ class.

[kubatp]

Your code looks like c#, in which case there's http://www.ogre3d.org/tikiwiki/tiki-ind ... lass+Mogre
It's a c# version of the http://www.ogre3d.org/tikiwiki/Euler+Angle+Class c++ class.

Hi Kojack, it is C# indeed. I already found that page, it was a nice surprise which saved me some time. I was ready to transform it to C#, but it wasnt necessary:)

Anyway, I have noticed that you are one of the authors. I want to say big thank you!