Qt3D 2.0 change object pivot

cRooked

Hey there community,

currently I am trying to make a scene where I import an car object into my scene and where i can oben doors etc.

So i stripped my model into a few models.. like doors, wheels and so on

Now that i have imported these models into my scene I want to animate them. And here starts the problem.

For example: I have set in Blender the pivot/origin of a door so that i can rotate it and get an opening effect. But the pivot point is not exported into the .obj file, but reset to (0, 0, 0).
When I export my model as .fbx file, the origin is exported fine.

Is there any possiblity to set the pivot point of a mesh in qml/qt3d or is there a module for importing fbx files? As far as I know Qt3D 2.0 only supports .obj files.
In Qt3D 1.0 there was support for more formats than just .obj.

I am using Qt 5.5

Kind regards,

cRooked

cRooked

nobody? i could really need some help

Carlito

Hi cRooked

usually applying a rotation matrix rotates somewhat around the origin / or an axis that goes through the origin.

So a workaround might be to translate the part to the origin, rotate it, and translate it back. (you still need to know the coordinates of the pivot though):

Qt3D::QTranslateTransform *TranslateToOrigin = new Qt3D::QTranslateTransform();
TranslateToOrigin->setTranslation(QVector3D(-x_pos, -y_pos, -z_pos));

Qt3D::QRotateTransform *doorRotation = new Qt3D::QRotateTransform();
doorRotation->setAxis( door_hinge_axis ); // axis as a QVector3D..
doorRotation->setAngleDeg(openingAngle);

Qt3D::QTranslateTransform *TranslateBack = new Qt3D::QTranslateTransform();
TranslateBack->setTranslation(QVector3D(x_pos, y_pos, z_pos));

// ... some code

Qt3D::QTransform *doorGeoTransforms = new Qt3D::QTransform();

doorSwingOpenTransforms-->addTransform(TranslateToOrigin);
doorSwingOpenTransforms-->addTransform(doorRotation);
doorSwingOpenTransforms-->addTransform(TranslateBack);

door_Entity->addComponent(doorGeoTransforms);

i'm sure this workaround could be optimized a bit, using just negative translate as translateBack or the like ...

hope this helps.
Cheers!