problem ellipsoid translation.

[moriwo]

I have the part that cannot be understood about createCollisionResponseAnimator.

This code, mesh fits ground.This appearance is correct.

Code: Select all

ISceneNodeAnimator* anim =Scene->createCollisionResponseAnimator(
	selector, meshNode, vector3df(0.5f,0.8f,0.5f), vector3df(0,-.5,0), vector3df(0.0f,-0.8f,0.0f));

This code, mesh is in the air.This appearance is not correct.

Code: Select all

ISceneNodeAnimator* anim =Scene->createCollisionResponseAnimator(
	selector, meshNode, vector3df(0.5f,0.8f,0.5f), vector3df(0,-.5,0), vector3df(0.0f,0.8f,0.0f));

The difference is a value of "ellipsoid translation".
I think that these results are opposite.

Upvector of my scene is (x,y,z) = (0,1,0).

The height of meshNode is 1.6
and the center(mesh origin) exists in the foot(Y=0).

so, I think ellipseoid center have to move to Y:+0.8.
it is not -0.8!!! because UpVector of this scene is (x,y,z)=(0, +1, 0).


I can't understand the sign is opposite.
How do you think this problem?

[Eigen]

Breaking news: It's not the ellipsoid that is moved with the translation, but the node! I checked Irrlicht's source and it works like this:

The collision spehere is moved and it returns the new possible position of the node. After finding the position, the translation is added to the new position vector and it is set to the node. So, it's not the ellipsoid that is moved against the node, but the opposite way. I think this should be mentioned in the manual more clearly.

Irrlicht source:

Code: Select all

...

pos = SceneManager->getSceneCollisionManager()->getCollisionResultPosition(
				World, LastPosition-Translation,
				Radius, vel, triangle, f, SlidingSpeed, g);

pos += Translation;

Object->setPosition(pos);
...

[rogerborg]

It's never occurred to me before, but that is indeed bass ackwards. I'd plump for just reversing it in SVN / 1.5 so that the translation is in the natural direction.