I am trying to make a Train Simulator in VR in Unity. But as the Train moves, the grabbable objects tend to move backward when grabbed. This creates a jittery effect. This might be because transform Values changes on fast movement and unity get slow in updating it. Does anyone know anything about it?
One possible solution to this problem is to use a Rigidbody on the Train object, and set the Interpolate setting to Interpolate. This will cause the Train object to interpolate its position and rotation, which should reduce the jittery effect.
Is your train a rigid body? If so, having rigid bodies inside of rigid bodies is a mess when working with physics. If that is the case it's probably best to not make your train a rigid body.
You should also check in what loops you handle your physics. Don't do this in the update loop. Try the FixedUpdate loop if you haven't. Sometimes you can also check if the LateUpdate does the job. But generally speaking. Physics goes into the FixedUpdate loop.
Another thing you can try is to have a stationary train. In this case, the environment can move around you.
Related
I have a simple game done using unreal engine 4,
The turret of the tank should turn toward the player pawn.
I made the blueprints code to build that, but the turret rotates quickly and incorrectly.
Video about problem
I tried to solve the problem many times without any results !!
Hope to help me.
There are probably a few ways you can do this, but you can simplify this quite a bit. I also suspect you can do all of it in the animation blueprint.
Simplify the first part (XDoMa.jpg) using the Find Look At Rotation node.
Break the output of this and create another rotator with the yaw from that node and the pitch and roll from the turret's world rotation (you're currently setting pitch and roll to zero in cDJ08.jpg, which you don't want to do in case the tank is on a slope).
To rotate the turret to point at the target, use the RInterp To node and connect its output rotator to a Set World Rotation node. The nice thing about the 'RInterp To' node is that you can set the speed. For a bit more realism you could use some simple maths to accelerate and decelerate the turret's rotation.
Another thing you'll want is a bool variable in the tank actor BP. Then you can use a branch in the animation BP to trigger the stuff above when you set the bool to true.
The key parts to this are the Find Look At Rotation and RInterp To nodes, and to do all of it in the animation BP.
I have been working on my own kinematic character controller for a while, but only recently learned that one should consider updating its position and rotation using Rigidbody.MovePosition and Rigidbody.MoveRotation instead of directly modifying the Transform component, which is what I am doing now. While my controller works fine, and does not cause any noticeable performance impact in my small games, I want to better understand the benefits of manipulating the Rigidbody component, and especially how this all works within FixedUpdate instead of Update.
To be clear about the supposed impacts on performance, Unity's manual on 2D rigidbodies says:
Any Collider 2D component added to the same GameObject or child GameObject is implicitly attached to that Rigidbody 2D. When a Collider 2D is attached to the Rigidbody 2D, it moves with it. A Collider 2D should never be moved directly using the Transform or any collider offset; the Rigidbody 2D should be moved instead. This offers the best performance and ensures correct collision detection.
Right now, my basic controller loop looks like this in the Update method:
Read the user's input velocity
Modify the controller's velocity based on this input (this velocity is distinct from Rigidbody.velocity)
Using Physics queries, sweep the controller's body against the appropriate collision layers by velocity * Time.deltaTime
Pick a collision resolution position based on a set of rules
Set the controller's Transform.position to this resolution position
I also have a method that moves the controller using Transform.Translate if no collision detection is needed.
As you can see, though my controller GameObject has a kinematic rigidbody attached to it, I never actually use it for anything. Unity's documentation on kinematic rigidbodies is conflicting, stating here:
Note: MovePosition is intended for use with kinematic rigidbodies.
but also here:
If isKinematic is enabled...The rigidbody will be under full control of animation or script control by changing transform.position
I am also unsure about how to manually check for collisions within FixedUpdate, as I have read that FixedUpdate can be called more than once per frame. Frankly, I thought FixedUpdate was only supposed to be used with dynamic rigidbodies to simulate real physics, and thus have only used this method for simple manipulation of those kinds of rigidbodies.
And then Rigidbody.MovePosition states that
2D rigidbodies have a fixed limit on how fast they can move therefore attempting to move large distances over short time-scales can result in the rigidbody not reaching the specified position during the next physics update. It is recommended that you use this for relatively small distance movements only.
What if my character needs to move a very large amount? Do I just set Rigidbody.position directly?
I guess I am trying to figure out how I can reconcile all of this logic to conform to what Unity says is best for performance. Perhaps I need to combine Update and FixedUpdate, but ultimately I am just hoping to receive some clarification and guidance regarding all of this.
player and object both have colliders and rigidbodies, object has position and rotation locked, player has only rotation locked. When the player goes to the blocks, the player goes through the blocks, although they do give a bit of resistance. To move the player im setting the rigidbody's velocity, and doing that in FixedUpdate.
i have no idea why this is happening, any ideas?
main part of the code is:
rigidBody.velocity = new Vector3(direction.x, rigidBody.velocity.y + (-Gravity * Time.deltaTime), direction.z);
(direction is determined by the WASD keys, and i'm using my own gravity)
First of all, you do not need to multiply the velocity by time.DeltaTime, because you are moving your object in the FixedUpdate() method; Which uses fixed time intervals since the physics engine does not run in sync with the regular game engine. Also, both objects do not need rigidbodies in order to collide with one another. I suggest looking at your collision matrix in settings and verifying that everything you need collision for is checked correctly. As others have said as well, check your kinematics on the rigidbody.
A last suggestion for working with your own gravity. Do not change the actual gravity value of the game engine. It is typically recommended that you use a multiplier variable and apply it to the constant gravity already set by the physics engine. If you are completely editing the gravity, than maybe consider using a character controller instead.
I guess it has something to do with what the documentation says "In most cases you should not modify the velocity directly, as this can result in unrealistic behaviour".
Try to use AddForce() or similar functions to alter the properties of the rigid body. Colliders etc will then work as expected.
I am making a simulation of some fish in a lake.
I am using rigid body as otherwise they move through the sides. But when they hit into the sides they rotate and then the script I have to set their rotation to 0,0,0 when they leave fails.
Your problem may be occurred by the fact that you are using unity's physics to move the fish but trying to set rotation directly. In this case movement and rotation of the fish are driven by Physics and forces, applied to the object. But you still can affect rotation and position if you reset all forces. Try looking here to learn how to remove forces.
Also when dealing with Physics in Unity, don't mess Update() and FixedUpdate() methods, because it may lead to an incorrect result.
When you say "hit into the sides" do you mean the sides of the simulated lake?
If so, one option might be to set the objects that denote the sides as "kinematic." Then you can detect when a GameObject (such as a fish) collides with it but it won't cause any physics reaction.
(ref: RigidBody)
I have a sphere build from multiple objects. What I want to do is when I touch/click an object, that object should find all adjunctive objects. But because none off them are moving, no collision detection can be used.
I can't find a way to detect these adjunctive objects even when the colliders do collide with each other, as I can see that in the scene. I tried all the possibilities, but none off them are working, because no objects are moving.
Is there a way to check for manual collision detection, or is there some sort of way to let Unity3d do the collision detection automatically?
You could keep a list of all those objects, then when your event happens you can send messages to all them to do what you want them to do.
Lets assume you want your sphere to break into little pieces. You send a Force message to the sphere. Then you use Newton's Laws of motion and find out how much velocity each piece gets. Remember velocity is a vector thus it has direction.
This is how I would do it and still keep the right amount of control over what happens in my game/simulation. Remember F = ma.
you could use RaycastHit (http://docs.unity3d.com/Documentation/ScriptReference/RaycastHit.html) for your collision, this also works on non-moving objects but it needs more performance
You can add rigidbody to every objects; when you touch one of them, give a force onto it, then it is going to move and trigger event of the adjacent objects.
for the reason you do not want to move the object you touch, you can cancel movement in the OnCollider or OnTrigger event handler function.
I managed to work around this by checking the distance from the selected object and all other objects that are part of the sphere. If the distance is below a certain value, then it is an adjunctive object.
Although this is certaintly not fool proof, it works without problems so far.
I am sorry I was not clear enough. Thanks for all the advice what so ever.