I want to have the friction of a Physic Material depend on the direction. I found this documentation from Unity 5.2 that lets you set two directions and friction coefficients but that is missing from the newest api. Is there a way to do this in the new version or am I going to have to do it manually?
I'm trying to use wheel colliders to provide similar functionality but they are behaving very strangely. They fall through the floor, jump unexpectedly, bounce weirdly.
This is a very good question as I was having the same problem a while back!
Unfortunately, what I have gathered from both unity developers and the current documentation is that the feature you described is not implemented into the current Unity engine as you have assumed.
Some work arounds that I would suggest is reverting back to a previous version of the engine if you are able or create your own friction system that would take data from the velocity vector of a physics object to determine which direction it is travelling. More information on finding a Physics object's velocity can be found on this page https://docs.unity3d.com/ScriptReference/Rigidbody-velocity.html
Best of luck on your Unity Project!
Related
I'm currently using photon pun 2 to learn simple 2d multiplayer.
Using PhotonRigidbody2DView is giving an 'elastic' movement to the player. The player goes forward a bit and then returns to the original position.
Here's the video:
https://youtu.be/HgFVsofVZcQ
Why does this happen and how do I solve this?
I tried using PhotonTransformView and PhotonTransformViewClassic but it is giving weird results. The players go inside each other and when one player collides the other, the other player starts jittering.
So I decided to use PhotonRigidbody2DView instead. Now the players don't go inside each other and the jittering is also not happening but the 'elastic' movement problem is happening.
This happens because the remote client uses the velocity of the rigidbody to reproduce the movement of the character is does not control. This makes it a bit independent from the lag but for arcade style movement (where direction changes are immediate), this doesn't work all that well.
Solutions to this depend on what you actually need. Networked objects combined with physics can be tricky to get right. For PUN 2, we didn't implement a solution to this case and assumed you'd tweak the PhotonRigidbody2DView as needed.
The Smooth Sync package in the Asset Store seems to do well and is a plugin to PUN 2.
Alternatively, the newer Photon SDK "Fusion" should do better and is state of the art as networking solution.
I'm looking for a little newbie advice on gamedev strategy and/or approach. I'm working on a game that uses Rigidbody physics in Unity and I've got a character interacting nicely with physical objects in the game world. The thing I'm trying to work through is that there are certain physical interactions that I want to control, but my own attempts to control them are conflicting with what Unity is already (correctly) doing.
For simplicity, let's just say I've got a Rigidbody-based player, and when certain Rigidbody-based objects collide with that player, I want to override where they deflect to. When I detect the collision and apply my own force with rb.AddForce(myForceVector, ForceMode.VelocityChange), Unity is also applying it's own force as a result of the same collision. I also tried setting the velocity directly with rb.velocity = myForceVector, which mostly works, but there are still situations where Unity applies force after I set the velocity so it's glitchy at best.
Other options I've considered are:
Use an additional, larger IsTrigger collision mesh to detect and handler the special type of collision I'm looking for before the actual collision occurs. That might work for slower speed projectiles, but likely will have the same issue for faster collisions.
Change the player to not being Rigidbody-based, which might work, but would require me to code a lot of the other interactions that are already working out of the box with Rigidbody physics.
Use RayCasting to detect when these special collisions might occur next and handle them before the actual collision. This is where I'm leaning currently.
Anyone have a recommended best practice for this kind of thing?
Thanks in advance!
The easiest way might just be to take full control. On the correctly timed press, disable the RigidBody and the Collider. Then just move it yourself to the target location. It's really hard to get precise control over a RigidBody -- every FixedUpdate(), it might be picking up force from collisions, and there can be many FixedUpdate() calls between Update() calls.
You could write a pretty simple coroutine using a Lerp() or Slerp() between the object's current and target position. That way, you could fully control how the object moves toward its target.
Just to follow up... I attempted to "take full control" as suggested in Alex M's answer above, but that ended up making a number of other things complicated in my specific situation. However, his comments about disabling the collider in the original question led me down a different path that ended up working well...
I ended up disabling the collider for the deflecting rigidbody upon impact and setting the velocity of the deflected body directly. That way, I was able to avoiding any additional force(s) applied from Unity while the collision was active. Once the deflected object was on it's way, I just had to reenable the collider.
Thanks, Alex!
I want to make an ocean simulation that is physically accurate.
The height and speed of the waves should be controlled by the keyboard at runtime.
In the ocean, there needs to be a boat that either moves along a path or is controlled by the keyboard.
So far I have made this simulation in Blender:
https://youtu.be/LJ6ncxv-k7w
The problems are as follows:
1. There is no collision with the ocean
2. There are no controllers for the boat's movement
3. I am able to control the waves, but not at runtime
I thought about switching to Unity because the user interface is obviously better, as it is a game engine. I do not want to use Blender's game engine as its future is uncertain at this point.
After reviewing the various Unity water simulation plugins, I came to these conclusions:
1. the buoyancy is great in most of them, such as in Aquas and SUIMONO
2. None of them seems to offer a physically realistic collision with the boat.
3. they do offer wave height control, but not much else as far as wave properties go.
4. Some of the plugins can be combined to get closer to satisfactory results.
My question is:
Should I go with Unity completely?
It seems perfect for my user control needs, but the plugins are lacking in the collision aspect. I came across this video, but no tutorial: https://www.youtube.com/watch?v=T0D_vrYm4FQ
Even if there was one, how could I combine it with the plugins?
Is there a way to build the scene in Blender and then import it into Unity?
Would I be able to control the waves and boat after importing them?
Thank you very much for your time and knowledge.
if you really means an ocean, i suggest you to check out NVIDIA WaveWorks. it's a C library and doesn't have an officially integration with Unity3D, but since you go this far for it, i guess maybe you'll have enough courage to trying make it into a useable plugin yourself.
I am experimenting with overlaying augmented reality objects over a pass-through image from the rear camera in Unity.
Has anyone experimented with overlaying objects with accurate tracking? I've tweaked the movement scale to get somewhat decent results but rotation is still not accurate and drift is a big issue.
I've had good luck with the augmented reality sample that ships with the latest tango. in my experience it does work the way you speculated where if you add items to the unity scene they are synced to motion detected by the device.
I believe the tracking and syncing function have improved since you asked this question originally because I've noticed an improvement since I got my tango devkit a month or so ago. there was an update a week or so later, with an immediate improvement.
I have found that some scenes track better than others, it seems to help for there to be additional scenery for it to track. in my workspace, a fairly cluttered apartment, it tracks well but in the neighboring identical apartment unit which is currently vacant and empty, it does not track as well. that could also be a product of the blinds hanging up in my unit that are not hanging up in the vacant unit, filtering out additional infrared.
I'm experimenting with placing 3D objects over the real time input from the Tango color camera.
One problem here is that the hardware color camera 'point' in a (strange) direction. I wasn't able to get the direction vector from the api until now. Your virtual camera for rendering the scene needs this rotation to render 3D objects properly.
There are augmented reality examples of Tango's Unity plugin:
https://developers.google.com/tango/apis/unity/unity-simple-ar
They solve this problem with a matrix that rotates the 3d camera.
It can be found in the Unity script "TangoARPoseController" (C#) that, when attached to a unity camera, rotates it so that it looks at the scene in the right direction. The matrix is obtained in the method "SetCameraExtrinsics" of that script.
Unfortunately, when I apply the matrix to my unity scene it does not produce a perfect overlay (actually it's quiet bad). But I have other sources of position input which may be the problem here.
However, until now I'm not sure if the matrix used in the examples is good enough for accurate ar overlays. Maybe it is just suitable for demonstration purposes. But it should be a good starting point for further investigation.
Are we talking about displaying the 'webcam' in the background as opposed to a skybox ?
Take a look at my GhostHunter repo. It includes a shader and a script for displaying the rear facing camera 'behind' the gameplay objects (like the skybox). It should be useable with Tango and it is better than the 'display on a mesh' technique I`ve seen others used.
https://github.com/NVentimiglia/Augmented-Reality-Ghost-Hunter
How to catapult animation in cocos2d.
Iam doing animation of streching stick like rubber, does not get any luck yet,
anyone knows please help.
Thank You.
It's hard to answer your question without more specifics. For instance, are you using one of the physics libraries (Box2D, Chipmunk) or are you rolling your own physics? Are you just trying to model a launched projectile (which is a simple parabola), or do you need to model the physics that actually launches the projectile (which will require a much more detailed model)?
If it's the former, as I said, the animation will just follow the arc of a parabola, but rather than computing the parabolic equation, it's probably easier to animate if you just give the projectile a velocity vector, and apply a gravity vector to it over time.
If it's the latter, I think you need to translate what you want into the physics involved. You mention a catapult, which is about levers, but then you mention a "stretching stick like rubber" which sounds more like spring forces, so the answer to your question is going to depend heavily on what exactly you're trying to achieve.