I have two Matrices;

1) object3D1: The source Object3D rotational matrix (getRotationMatrix())
2) object3D2: The destination Object3D rotational matrix (getRotationMatrix())

I would like to slowly rotate the source object to match the rotation matrix of the destination object frame by frame, so both rotations are exactly the same (both objects are facing the same way).

I'm guessing I can use object3D1.getZAxis() and object3D2.rotateAxis() but how do you do the calculations?

Or can I use Matrix.interpolate()?

Yes, because jPCT isn't thread safe.

Yep I learned that the hard way 

I can confirm that if translations/rotations are changed outside of the rendering thread, the objects can sometimes render in the wrong location at random frames.

Use variables to store the orientation in OnSensor(), and do all camera/object translations and rotations in onFrame() using those variables.

I tried that code and it helped centering the projectile to the players center, but the projectiles were all facing/shooting towards -X.
So I added "bullet[n].setRotationPivot(player.getZAxis())" to fix that, but the projectile is still offset depending on the YAxis of the player. (Same as before)

If I point the player towards:
+Y = OK
-Y = OK
+Z = OK
-Z = OK
+X = The projectiles are slightly offset to the left of the object
-X = The projectiles are slightly offset to the right of the object

Current code:
bullet[n].clearTranslation();
bullet[n].translate(player.getTransformedCenter()); // getTranslation doesn't work properly
bullet[n].getRotationMatrix().setTo(player.getRotationMatrix());
bullet[n].setRotationPivot(player.getZAxis()); // Added because the projectiles were pointing towards -X
//bullet[n].setRotationPivot(player.getRotationPivot()); // No good. All projectiles point to -Z


I am rotating the player per frame using just rotateAxis which is working well. (not using Object3D.rotateY etc..)

// Horz
player.rotateAxis(player.getYAxis(), (fSenseYaw*0.1f)*fDiv);
// Vert
player.rotateAxis(player.getXAxis(), (fSensePitch*0.1f)*fDiv);


I am moving the projectile per frame using:
// Move in its direction
SimpleVector sv = bullet[n].getRotationPivot(); //sv = bullet[n].getZAxis(); (getZ doesnt work properly)
sv.scalarMul(10.0f);
bullet[n].translate(sv);



Thinking the object was off center, I tried correcting it by translating the mesh (Z ways) and then calling translateMesh() but that didn't help. The object itself became way off the camera's center depending on the Rotational Axis.

I also tried replacing the object with a simple cube primitive (loading it with just two lines of code), with no pre translation or rotation:
player = Primitives.getCube(1);
world.addObject(player);
But the projectiles are still offset when point towards -X or +X

I can't figure out why that is happening. I guess I could correct it on the fly by translating Z depending on the XAxis.x value, but I would like to avoid that kind of correction if possible.

Installed the Beta and it made a huge improvement!

The Ellipsoid function barely causes a framerate drop now (if at all), plus overall rendering performance has more than doubled. I even tried placing 128 objects in the scene and the frame rate is surprisingly maxing out at 60FPS most of the time.

That's the performance I was looking for, thanks

One option would be to move the camera to the location of the initial pinch, or translate/move the object at every frame aligned in ratio to the pinch origin.

Or if you want the object pre-translated, you can load the object, translate it into position, then call rotateMesh to update the meshes translation. Not 100% sure if that would work but I imagine it would.

Hmm I guess I could place the Move variables into a simpleVector then scaleMul it to generate a destination. I'll use that technique if I need Y movement

I'm trying to rotate an object so it's facing the way it's moving.

Is there a function in jPCT or Java that can calculate the rotation angle based on an object's translation movement?


If the object is travelling up Z using translation(0,0,2), the angle would be 270 degrees.
If the object is travelling down Z  using translation(0,0,-2), the angle would be 90 degrees (or PI/2).
If the object is travelling up X  using translation(2,0,0), the angle would be 0 degrees.
If the object is travelling down X  using translation(-2,0,0), the angle would be 180 degrees (or PI).
If the object is travelling down X and up Z using translation(-2,0,2), the angle would be 225 (270-180).