I'm new to 3D design, so this might be a silly question.
I have trouble simulating wheel camber using rotation with Quaternion.
What I understand is that the rotation of the WheelCollider occurs along the X axis, whereas in my case the "visual wheel" is rotated 80 ° along the Z axis so the rotation occurs along the Y axis.
This code works well with the FL wheel because its axis is aligned with the collider axis, while it doesn't work with the FR wheel.
collider.GetWorldPose(out Vector3 position, out Quaternion rotation);
visual.transform.position = position;
// initialVisualRotation is the wuaternion rotation of the visual at Startup
// in this case: X=0 Y=0 Z=80
visual.transform.rotation = initialVisualRotation * rotation;
These are my local and global rotation axes for the right front wheel (FR).
How can I "adjust" the wheel rotation without change initial axes (as I did for the FL wheel)?
Are there some quaternion operations to adopt in these cases?
A bit of workaround for not having to deal with messed up transforms is to make object a child of another empty object.This way you can make parent object rotated to make wheel tilted but Child( actual wheel) will have its original axis always not messed with and so you can use simple script to always rotate it around same axis that is always going to be the same despite whole system(hierarchy of objects) being " tilted".
Parent is responsible on rotating around one axis and child around another.
I think you need to take a step back and arrange your prefabs this way as it seesm you did not.
Related
I have a Cube in Unity. I'm moving and rotating the cube and I want to track the rotation around a special axis.
The Application is a Holo Lens 2 Application and I'm grabbing an Object with my hand. I then want to rotate the Object in my Hand around one of its local axis. I need that rotation around that axis, meaning a float, to rotate another object around its oft local axis by the same amount.
Any Idea how to achive this?
Goal:
Calculate a rotation, that can be used, to correct the Transform of the bones, so they get rotated as expected when manually rotated.
In Detial:
Character's bone Transform is not imported to Unity correctily, ie. the left hand's Z axis does not looks towards the top of the hand, but backwards, while the right hand's Z axis looks forward.
The bones default rotation is not the same as you would expect if you have seen the rig in another application before.
I had the idea to create a class, that puts the character in T-Pose, then maps the bones rotation.
(I would assume that Unity does something similiar under the hood, that's how I got the idea.)
So the class would be used with an API like this:
/// This should return the rotation, where the bone pointing forward rotated by rotation.
/// Ie. when rotation = Quaternion.Identity the left hand should look forward.
Quaternion CorrectRotation(HumanBodyBones bone, Quaternion rotation)
{
return Quaternion.Inverse(tPoseRotations[bone]) * rotation;
}
The problem is, that I can't seem to find a good way to map theese rotations.
My last attempt was this:
Vector3 boneDirection = (boneTransform.position - parentTransform.position).normalized;
Quaternion mappedRotation = Quaternion.LookRotation(boneDirection, parentTransform.up);
As you can see in this image, with this method the hands look in the same direction, forward, but still not rotated correctly, they have an offset from the desired result. (The correct rotation is shown by the purple hands.)
When given other rotations, the hands follow with the same offset, so other then this unwanted offset they work correctly.
So basically, I would appriciate any help to fix my problem, either this way, or with a different solution, that works with different rigs.
In the scene, I have a long chain of children that are connected via hinge to their parent. For my code, I need the position of the hinge anchors in world space, so I use:
public Vector2 hingeVector => hinge.anchor + (Vector2)gameObject.transform.position;
For the first hinge, that code gives the correct position. But for the second hinge this happens:
The red point is the vector I get, the blue point is the actual position. As you can see, it's a somewhat small but still problematic difference.
Is there any way I can fix this? I couldn't find anything like this online.
You need to add the object's rotation
The anchor values are axis aligned and aren't affected by rotation, but in order to calculate the anchor point in world space, knowing the transform's position, you need to rotate the anchor point values by the object's rotation then add it to the position:
Vector2 p = hinge.anchor.Rotate(gameObject.transform.rotation.eulerAngles.z)
+ (Vector2)gameObject.transform.position;
I have a finger object. It is just three cubes representing the finger parts.
The 2nd cube is the child of the 1st one. And the 3rd cube is the child of the 2nd one.
This is the heirarchy: Cube1 -> Cube2 -> Cube3
My goal is to apply a rotation angle to the first cube and let the other cubes do the same locally.
Example: Apply 30 degrees Z rotation to the first cube, 30 degrees Z rotation to the 2nd cube, and also the 3rd one.
This will make a finger that look like this:
(Forgive me if it doesn't look like a finger)
In every Update() frame, I will change the angle (it's just one number) and it will rotate every cube for me.
My question is:
How do I make all these cubes collide properly with other objects?
I tried putting the Rigidbody on all of them and set isKinematic=false because I want to transform them myself. But I still cannot use transform.rotation to update my rotation because it will miss the collision with a ball very easily (especially the tip of the finger because it moves faster than other parts). Continuous detection doesn't help.
So I tried using rigidbody.MoveRotation() and rigidbody.MovePosition() instead, which is a pain because they need absolute values. They worked but the animation is so jumpy when I change the angle quickly.
I'm guessing that the animation is jumpy because there are many Rigidbodies or because the physics engine cannot interpolate the position of each box properly when I use MoveRotation() and MovePosition().
I need to use MovePosition() also because when I use only child.MoveRotation(transform.parent.rotation * originalChildLocalRotation * Quaternion.Euler(0, 0, angle)), the position doesn't move relative to the parent. So I have to compute child.MovePosition(parent.TransformPoint(originalLocalPositionOfTheChild)) every frame too.
I encountered another issue with hand-object interaction using a Leap Motion device. In particular, I use the LM to perform orientation manipulations on virtual objects.
I want to use the difference between the current and last orientation of the hand to manipulate the object:
Quaternion relativeOrientationHands = Quaternion.Inverse(currentHandOrientation) * updatedHand;
transform.rotation = transform.rotation * relativeOrientationHands;
It works fine, however the problem is that, let's say I rotate the object 180 degrees around the x axis (after that, y is pointing downwards). If I release the object afterwards, and grasp it again, the orientation changes get from then on applied to the new orientation of the object which is super confusing to use. (Original: turn hand to the left - object turns counter-clockwise; After: turn hand to the left - object turns clockwise)
Unfortunately, I don't know the math to fix it, but maybe someone can help me out. How can I apply the orientation changes of the hand to my virtual object, with respect to the default object orientation using Quaternions. Maybe, something with normal vectors?
EDIT:
The 3 figures illustrate my problem. The first figure shows the object in its original orientation (x-right, y-upwards). I turn the cube 180 degrees by rotating my hand 180 degrees clockwise around z (blue axis), after I release it, x is pointing to the left and y is pointing downwards (figure 2). If I grasp the object (figure 3) in its current orientation, and let's say I would want to perform a 90 degrees clockwise rotation around the y-axis. In figure one, I could do that by moving my hand 90 degrees clockwise. However, I changed the orientation of the cube with my previous manipulation. Therefore, I would have to perform a 90 degrees counter-clockwise rotation with my hand to move the object in clockwise direction, because the y-axis is flipped (figure 2-3). I always want that turning your hand 90 degrees clockwise results in a 90 degrees clockwise rotation of the object regardless of its current orientation.
Thank you very much
Best
R.Devel