Develop Reference

Get Unity Blend Tree to update based on player rotation (mouse position)

I'm working on the animations for a character in a top down game. I got the animations to work when the player is moving forwards towards the top, however, whenever I rotate the player with the mouse (to aim) the forward animation is now left/right, etc, etc. I'm using Unity3d and C# with blend tree animations.
The code I'm using is straightforward:
animator.SetFloat("VelX", playerInput.Horizontal);
animator.SetFloat("VelY", playerInput.Vertical);
I can't figure out how to make the forward animation play whenever I'm moving TOWARDS the mouse position.
My Solution:
var heading = Input.mousePosition - this.transform.position;
var distance = heading.magnitude;
var dir = heading / distance;
animator.SetFloat("VelX", playerInput.Horizontal * Mathf.Cos(dir));
animator.SetFloat("VelY", playerInput.Vertical * Mathf.Sin(dir));
Any help would be appreciated.

You may have figured this out already but I just had the same issue and I just found out a way to do this. Hopefully it helps others.
Vector3 inputVector = (Vector3.forward * Input.GetAxis("Vertical")) + (Vector3.right * Input.GetAxis("Horizontal"));
Vector3 animationVector = _playerModel.transform.InverseTransformDirection(inputVector);
var VelocityX = animationVector.x;
var VelocityZ = animationVector.z;
this._playerAnimator.SetFloat("x", VelocityX);
this._playerAnimator.SetFloat("z", VelocityZ);
I my case I have my movement script on a parent empty object. This object rotates the child player model, which is the one getting animated. If you do this then you will need to reference the player model like I am doing. Otherwise you can you transform if you are using the parent object.
I am using a character controller on my parent object not a rigidbody, but it may work the same either way.
From my understanding the key part is 'InverseTransformDirection' which is taking my physical world horizontal and vertical vectors and then converting them based on the rotation of my player model. This then makes the movements be relative to the players rotation rather than the worlds rotation and I can move backwards or strafe correctly as I am moving my mouse for rotation and wasd for movement.

Set direction of rotation Unity C#

I am trying to make a spin wheel that is divided into 6 sections. Each section is marked with a gameObject that is centered in that section. After the player spins the wheel, it will rotate until its starts stopping and then the wheel moves and stops in the center based on the section that was selected (Randomly). I used the following code to rotate the wheel towards the 0 on X axis. this code works fine and the wheel rotates fine, but only if the selected section was on the positive X axis.
float rotateFloat = (((randomReward + 1) * 60) - 30) - transform.rotation.z;
Quaternion targetRotation = Quaternion.Euler(new Vector3(0, 0, rotateFloat));
transform.rotation = Quaternion.RotateTowards(transform.rotation, targetRotation, f_difX * Time.deltaTime);
I did some digging and found that Quaternion.RotateTowards()finds the closest way towards the target and rotates using that direction (This caused a problem with the direction of rotation).
Example (Follow image): The player swipes and randomReward (Number 5 on spin wheel) and the wheel starts rotating. When the wheel slows down, it starts moving towards the center. Then it will stop spinning along the direction of the swipe and will rotate towards the other side (Because the distance to the center is closer from the left side).
How can I set it to follow the same direction of the swipe regardless of which is closer to the center. And maybe if there is a better way to do this, please enlighten me. Thanks.

I think the easiest way to rotate a GameObject is by using:
float Speed = 1f;
void Update()
{
// Rotate the object around its local X axis at 1 degree per second
transform.Rotate(Vector3.right * Time.deltaTime * Speed);
}
You can read more about his here
It can happen sometimes the center of the GameObject it´s not placed in the center of the mesh or sprite. If you can´t modify this for any reason, what you can do is place this model/sprite as a child of an Empty GameObject and then attach the rotation script to the Empty GameObject.

While i understand that you don't want people to rotate the disk to the reward they want. Why do you use a random reward and go through the trouble of lining the rotation to the reward?
You should be able to say catch a 'swipe time', then do some math to it (say so it turns at least once if the screen touch time is very short) and then add a random range to it, that is within the circumference of the disk. Then when the disk is done spinning do a ray cast at the top location to determine the reward? (could also link the spinning time to the swipe-time, so that the reward is offered in somewhat the same time interval).
//this comment would have been made as a comment if i would have had the rights to do so, as i think this response may help the question asker, it is provided as an answer instead. i do hope this doesn't piss any one off to much :(

How can I find the rotation of the head in Google Cardboard Unity3D?

Hey guys how do I find the rotation of the phone with Google Cardboard SDK in Unity3D, like the way the persons head is facing? I need to find if it is facing more towards the east, the west, or the north. Do I find the rotation of the head, or the parent Main camera?

The Cardboard class contains a property called HeadRotation which is a Quaternion.
Quaternion crtRot = youCardboardController.HeadRotation;
To use its rotation like you'd in Unity with directional vectors you may simply multiply it by Vector3.forward.
Vector3 lookDir = crtRot * Vector3.forward;
Visualizing the vector in editor might help narrow down issues
void Update () {
// ..
Debug.DrawRay( pos, lookDir * 100, Color.blue );
// ..
}
From here you only need to know where North is, in meaning of the facing vector. Do a Vector3.Angle() and you have the angle between your avatar's and North's vector. You might want to evaluate both vectors with their y axes set to 0.
You could also use Vector3.Dot() (the dot product) to determine how much both vectors look into the same direction.
I had an issue with HeadPosition, which wasn't updated properly. So if you operate from HeadPosition keep in mind it may stick to 0,0,0 .

Take Head.transform.rotation - that's the orientation of the user's head.
I'm not really sure what do you mean by North or West. If the mobile device has a magnetometer, then maybe you could read it's data to determine where North is, but I've never done that

It would be the rotation of the Head object, although the Main Camera usually has the same rotation.
But if you want the direction relative to the real world, that information is not available in the SDK. The compass cannot be used because of the magnet, so there is no way to get the real direction.

Just take the rotation angle of the main camera in the scene. It will gives you the head rotation angles with respect to x, y and z axis.
In GVR based VR scenes the system is internally rotating the camera with respect to our head movements. So it's easy to get the head rotation using main camera rotation angles.
For that,
//local rotation of the Transform of the camera
Camera.main.transform.localEulerAngles.y
//The world Y rotation
Camera.main.transform.rotation.y

Rolling a sphere relative to Camera Rotation

I'm working on a new control scheme for the Oculus Rift that utilizes the tilt of the headset to move the player. Meaning, you tilt your head back and forth to go forwards and backwards, and from side to side to strafe. The camera is tied to a rolling sphere, as that gave it a nice sense of acceleration, and feels a bit like kind of flying around. So far, it's working quite well, but only on the global axis. So if you turn to the left and tilt your head forward, you still go forward according to the starting position (Which if you're facing to the left means you'll go right). I'm trying to fix it so that you can go forward and strafe relative to the direction the camera is facing, but with no luck. I have a strong sense that it's something ridiculously simple, but I just can't seem to find it. Any help is very much appreciated!
Here is what I have on the rolling sphere right now:
public GameObject RightCamera;
void FixedUpdate(){
float angleX = RightCamera.transform.eulerAngles.x;
angleX = (angleX > 180) ? angleX - 360 : angleX;
float angleZ = RightCamera.transform.eulerAngles.z;
angleZ = (angleZ > 180) ? angleZ - 360 : angleZ;
Vector3 movement = new Vector3 (-angleZ, 0, angleX);
GetComponent<Rigidbody>().AddForce (movement);
}

There's an easy way to do this. Given the orientation expressed as a quaternion (or 3x3 Matrix) compose it with a unit Y axis vector.
The resulting vec3's X and Z values are your forces. No need to involve Euler angles, which will almost certainly start hurting you as your approach a 90 degree angle from vertical.

Finally solved it! I used
GetComponent<Rigidbody> ().AddForce (RightCamera.transform.forward * angleX);
GetComponent<Rigidbody> ().AddForce (-RightCamera.transform.right * angleZ);
And now the sphere rolls relative to the camera.

XNA Rotating a tank properly

Im making a 2D game where the player controls a tank.
I can make the tank, and all, but whats really messing with my mind is how to make it rotate accordingly.
I want it to behave just like the Wii game, Tanks.
Fixed directions, and with no real front and back on the tank.
Driving up, then left should make it rotate to the left.
Driving up, then down should not make it rotate, just drive the other direction.
I red a tutorial a while back about some way to do that by dividing the degrees into 2 180 degree parts. But i have simply not been able to find that damn site again.
I hope you guys are able to understand what im trying to say.
Thanks in advance :)

I assume you're drawing your tank as a sprite? In that case there's an overload of the SpriteBatch.Draw method that allow you to specify the rotation angle around the origin.
SpriteBatch.Draw overload
Here's an example on how to use it from MSDN
The example above will keep rotating your sprite, so you will need to add some custom logic so it will only rotate it according to keyboard input. Here's a simple example on how to check for keyboard input. So add logic that checks if the right or left button has been pressed, and update the rotation angle if they have. If it's the up or down button that has been pressed you simply modify the position of your sprite.
I hope it makes sense, otherwise just let me know.

I think what you're looking for is simply the best way to minimize the rotation of the tank, modulo 180 degrees.
I would use the angle between the desired movement direction and the tank's current direction to start. Make sure this is the minimum angle, then compare that with the angle between the tank's current direction + 180 degrees. Something like:
// smallest angle between the current direction and the desired direction
minAngle1 = Math.Abs(Math.Min(tankAngle - desiredAngle, desiredAngle - tankAngle));
// smallest angle between the opposite direction and the desired direction
oppositeAngle = (tankAngle + 180) % 360;
minAngle2 = Math.Abs(Math.Min(oppositeAngle - desiredAngle, desiredAngle - oppositeAngle));
// get the smaller of two to rotate to
if (minAngle1 < minAngle2) {
// we know that we should rotate the current direction to the desired direction
} else {
// rotate the opposing direction to the desired direction
}
Note you'll need to play with your rotation signs to ensure you're rotating the right way. Also, I've assumed you know your rotation angles, if you have vectors you can simplify this a little bit by using the dot product between the two vectors instead of the angle for comparisons.

Is your problem with the direction of movement based on the angle they have rotated?
Vector2 moveDir = new Vector2(Math.Cos(rotation), Math.Sin(rotation));
position += (moveDir * speed);
Speed here would be a number for how fast you want to move in that direction. position is another Vector2 for the position of the sprite. As Tchami says you can draw it with the rotation using the SpriteBatch.Draw overload. Rotation for the the Cos and Sin methods should be in radians but I think Draw should be in degrees if I remember correctly. MathHelper.ToRadians(degrees) and MathHelper.ToDegrees(radians) should solve that.
There is lots of XNA tutorials and examples on the site http://creators.xna.com/en-US/education/catalog/