I need a curve cylinder collider for my curve water pipe model so that my player red cube can pass easily through.
I tried mesh collider it doesn't works and also tried another trick where I build 2 models in blender one for mesh render, one for collider. one as a whole one in 9 chunks cause mesh collider was not working on whole one object check pic no:1 and check pic no:5 where after exporting both models to unity I applied mesh collider on all 9 chunks of pipe separately to get perfect results in pic no:5 results of collider look's perfect but not working perfect the red box Player can't pass through the pipe
Collider doesn't let the player get inside and out from another side as shown in pictures. I need a perfect collider for my curve pipe so that my player can easily pass through. In pic one I showed that after applying mesh collider results. In pic two I showed I build my model again but in 9 chunks as one chunk is selected you can see, To apply mesh collider on all 9 chunks separately to get good results. In pic 5 I showed final result it looks good but not working the collider is not letting my small red box player inside the pipe and pass through it. In pic 3 I am aiming. In pic 4 I fire and showed that our player does'nt get in the pipe.
This problem is caused because Unity is turning your Mesh into a convex shape, which removes holes from the tube. It will also reduces the vertex count down to 255 triangles, the maximum for a convex mesh. That is why the collider gets so deformed in the first picture.
There are 2 main options for you here, because tubes are inherently non-convex shapes.
Make sure Convex is not checked on the mesh collider and that there is no rigidbody on the tube. Then, the cubes should be able to enter the tube. However, this will mean that other MeshColliders will not be able to collide with the tube. If you're only colliding it with BoxColliders, SphereColliders, or CapsuleColliders and so on, this should work fine.
Break up the tubes into a series of convex shapes, and make each one a separate MeshCollider. Then the situation you have here should work fine.
From the documentation of MeshCollider:
Convex - Tick the checkbox to enable Convex. If enabled, this Mesh Collider collides with other Mesh Colliders. **Convex Mesh Colliders are limited to 255 triangles. **
...
Mesh Colliders that do not have Convex enabled are only supported on GameObjects without a Rigidbody
component.
Related
I'm using Unity Engine to make a space exploration game. I have to implement the collision system for the planet I made with quadsphere and quadtree LOD, I thought of two ways:
Generate a BIG mesh collider for the hole planet and keep the collision activated only for the face that the player is in (the planet has 6 faces). This works fine because the mesh is created only one time, but the game keeps a mesh collider bigger than needed in the scene.
Use the quadtree LOD and create a new mesh collider every second, but just for the high resolution terrain near the player. The mesh collider used in this option is way less bigger than the first option, but is updated every second.
Which way is more approachable? And there are more efficient methods than these two?
I have a mesh that updates it's shape according to the user's input, how can I get the collider to match the new shape of the mesh ?
As an important note : the mesh is always always convex ( no exceptions ). I saw that it is important in order for the collider to work properly.
I have found the following video that does it here but the collider is simply erased and recalculated for each frame by doing meshCollider.sharedMesh = null and then meshCollider.sharedMesh = updatedMesh.
Since I am already calculating the position of each vertex, edge and triangle of my mesh, is it possible to me to use those values for the mesh collider ?
No way to do it as colliders do not have constructors for this. What you are doing is explicitly frowned upon in unity docs
'You should not modify mesh geometry that is used for colliders because the physics engine has to rebuild an internal mesh collision acceleration structure every time you change the mesh. This causes a substantial performance overhead. For meshes that need to collide and change at runtime, it is often better to approximate the mesh shape with primitive colliders like capsules, spheres and boxes.'
One work around is to use InvokeRepeating on your method and create the new mesh collider every second instead of every frame (you can test and make it 0.1 second , 2 second, whatever can run without frame drops). You can call CancelInvoke when the object is done shifting.
The Problem: Mesh colliders on some rigidbody objects are passing through colliders on other objects.
Things I have tried:
With the assumption A is a GameObject with a RigidBody attached and B is a normal GameObject with a collider.
Give A a convex mesh collider
Give A a non-convex mesh collider
Give B a convex mesh collider
Give B a non-convex mesh collider
give B a box collider
give B a convex mesh and box collider
give B a non-convex mesh and box collider
Adjusting the weight of the rigidbody
I have tried all of these in all combinations of A and B.
In addition,
Colliders are not marked as triggers
All objects are on the default layer (0)
Checking isKinematic; doing this seemed to make gravity stop affecting the object, so I have left it as false.
Constraints: I want A to use a mesh collider since most of the objects involved are moderately complex, and fitting other colliders to them would take a while.
Weird Behaviour: I have some objects with both rigidbody and convex mesh collider where the collision is working fine with a non-convex mesh collider. This is inconsistent with other gameobjects. The objects have all of the same settings.
I am using unity version 2019.3.11f1 if that is relevant.
The object being used are from this package. Specifically, the filing cabinet with rigidbodies on the drawers works fine. The desk, office chair, pen, and open laptop all fall through the "floor" (a cube with all of the above colliders tested on it).
Do you have 'isKinematic' checked on the objects with rigidbodies that are going through other colliders? If so uncheck it so that external forces affect it.
edit you also need to click convex on the mesh colliders if they are colliding with other mesh colliders, Convex Mesh Colliders are limited to 255 triangles, are the objects that are not passing through have more than 255 triangles in geometry?
I am Assuming you have set your Collision Detection to Discrete In your gameObject's RigidBody, if so, please make sure to select Collision Detection to Continuous In your gameObject's RigidBody.
Reason Why this is not working
You are trying to use collision that has (speed > your Computer's frame speed) so, the frame is not catching the collider properly some time catches and some time fails to catch.
You are moving your GameObjects with tranform.translate or position etc. If so then make sure to use Rigidbody Related function for Positioning, rotating.
Solution Image For First Problem
I'm assuming
-you game object which contain the mesh component is very small ( bellow 0.7 size(x,y,z) so the game engine is little difficult to detect it)
and also
for the colliding objects at-least one rigid-body component must be attach to one object
This seems to be a common big problem, and I have been struggling with the same issue for days, and have finally fixed it, so am feeling like I should highlight one important thing:
move Rigidbody via MovePosition, not via just changing its position field directly, nor via changing position of GameObject holding it.
Changing position via "wrong" ways will "teleport" your rigidbody, physics won't fully work on it in that case.
How to get/generate a proper mesh collider in Unity using a model exported from Blender (.obj/.fbx)?
This is my second day using Blender and I'm hitting a roadblock. I've tried fiddling with the Rigid Body Collisions, i.e., setting "Shape" to Convex Hull and "Source" to Final/Deformed (Blender docs specify that these two settings capture modifiers), I've tried "Generate Colliders" inside Unity and the mesh collider always comes out as above. A box.
How to assign mesh collider to the exact mesh? I started with a circle and used a boolean modifier to create the cutout. Desire is to have the mesh collider around the mesh exactly, meaning no collider on the cutout. How to do this?
Make sure you have a Mesh Collider component on your object with the correct mesh set. Watch out for the convex parameter for flat objects, as it can sometimes fail and give you a box collider instead.
Edit:
I just noticed you said you were using a RigidBody, which means you need to have Convex set. A solution to this is to make a second mesh in Blender with a third dimension to it, then set the flat one on the Mesh Filter and the one with thickness to the Mesh Collider.
In importing a .obj or a .fbx, select the asset. make sure you have generate colliders selected.
Here I have imported an FBX into unity, but there are no colliders.
Sellect the asset, and turn on generate colliders if you want a collider around the mesh:
Hello Peeps (first post yay).
I have just started to learn about unity and still going through various tutorials and learning the interface along with C#.
I am running Unity 4 and downloaded a free asset from the Unity store:
https://www.assetstore.unity3d.com/#/content/3174
The Problem.
I created a Plane in Unity.
Went to the Character and created colliders and imported it as a humanoid.
Then added a rigid body = The character fell through the plane
I then added a Mesh collider and attached the mesh for the character to the collider. The mesh does NOT align correctly to the character = the character fell through the plane.
I then tried box and capsule colliders and they worked fine. Attached these and the character would not fall through.
I then tried a character controller = Character did not fall through.
I want to have an accurate mesh for this test character so when an enemy hits him, there is an actual hit.
I have tried several other free characters from the store and they all have the same problem. Can someone please tell me how I can fix this? It seems I just either doing something completely wrong, missing a step or just plain lost.
Link below to image of the issue taken:
Using a mesh collider on a skinned, animated character is a wrong approach. Mesh colliders are generally used for environment geometry and rigid objects. This is all due to the amount of work it is needed for the Unity engine to accurately calculate the shape of the mesh collider, based on the provided mesh. More triangles means more work, and for the reasonably complex low poly character mesh of 10k to 30k triangles it is clear that the fps would most definitely drop to an unplayable level.
For our game we are using all primitive colliders, distributed on the adequate bone game objects. So, head bone has a sphere collider, spine has a box collider (for lungs), forearm has a capsule collider etc. That way,with a little bit of scripting, you can detect a hit and know exactly what part of body is damaged.
If your collider doesn't exactly match your mesh, then it's likely that you have the mesh applied to the wrong part of the object.
Try applying the Mesh Collider to the mesh, instead of the complete object.
You have a pretty complex character mesh, so using mesh collider probably isn't the best way to go. In many cases, character controller or capsule collider works fine; otherwise, you can just use compound collider and create a box or a sphere around various body parts of the character.
This once happened to me. The mistake i made was, i applied the mesh collider after i did some rotation and scaling. So i added the mesh collider as soon as i imported the model. And then it should be alright when you scale/edit the model. Also check with right/left handed co-ordinate system with unity and 3D MAX/Maya.