koobas.hobune.stream
[Trackball] Rotation around 2 axis
Hi,
I'm trying to simulate a trackball by allowing a sphere to rotate around the x and y axis. I did a small piece of code to make my sphere rotate along those 2 axis simultaneously :
void Update ()
{
prevAngle.x += 5;
prevAngle.y += 5;
transform.eulerAngles = new Vector3(prevAngle.x%360,prevAngle.y%360,0);
}
I was expected my sphere to rotate in "diagonal" but it is not the case - the movement is very weird.
I modified a bit the previous code in order to rotate only along the x axis and I was surprised to notice via the inspector that the x rotation value is not the only one to be update, sometimes the y and z values jump to 180 and then back to 0.
I do want the x and y rotation values to be the only one to be modified and I want to be able to compare between two updates the delta angle for the x and y axis.
I tried to use the Quaternion classes with the eulerAngles but I got a new problem, the x value freeze at 90 - cannot understand why.
So how can I make my sphere rotate along the X and Y axis and be able to calculate the delta angle for each axis ?
Thank you
I think you need to move to relative rotations. Euler Rotations hard set like that won't give you what you want, (I'm imagining it looks a bit like a figure of 8 or a spiral, as you're effectively changing the axis with one and rotating with the other like seasons on earth).
transform.rotation=Quaternion.identity;
transform.rotate(new Vector3(prevAngle.x,pRevAngle.y,0),Space.World);
will give probably smooth rotations although the axes may be wrong(I suspect x and z). You may need to reposition your sphere afterwards (?). alternatively, it may be easier to use a use $$anonymous$$athf.Sin and $$anonymous$$athf.cos to calculate a position around the sphere which it then looks at (transform.LookAt(wherever,Vector3.up)).
Yes I did. The problem is the same, when you Rotate only along the x axis the y and z angle values are set to 180 for a short times. It seems that this modification occur when the x angle is equal to 360.
this.transform.Rotate( .5f, .5f, 0 );
This code rotates my sphere quite good, I don't know hat happens to yours. Please explain the weird movement you are experiencing.
If I do this.transform.Rotate( .5f, .5f, 0 ) and then Debug the eulerAngle.x I can see that the value goes from 0 to 45. then to 0 then right after 0 the value change to 360 and then decreases etc. The x angle values update is weird, it's not like the value goes to 0 to 359 and then to 0 etc.
So it's not possible to compute and delta angle between two updates because sometimes you obtain strange values. I don't only want my trackball to rotate, I want to be able to know at each frame the angle delta for each axis in order to use those values to compute my main character speed for each axis.
