ARCore collider on generated planes - unity3d

I'm just playing around with AR core and want to have an object flying around the room and able to land. I'm unsure about how to add colliders to the planes that ARcore is generating based on the visuals on the room. Would this involve instantiating box colliders on the planes somehow?

The ARCore SDK's trackable planes are essentially identified flat surfaces such as the ground or a tabletop.
You can ask the SDK for a list of points for each trackable plane's boundary polygon (retrieved in clockwise order) and create a mesh from those points via triangulation. With the mesh ready, create a GameObject and add a MeshCollider component that references it.
I've created a free Unity plugin that does exactly this. Feel free to use it: https://github.com/jonas-johansson/ARCoreUtils.
I hope that helps!

Assuming you are doing this in Unity, you may want to use a Mesh Collider on the surface instead of a Box Collider.
I'm not sure about ARCore in Unity specifically, but in other AR frameworks it works something like in the attached screen shot, so I imagine it would be similar.

Adding a rigid body to the object causes gravity to be applied set gravity to 0 on the object rigid bidy. That will stop it falling away

Related

Cinemachine Collider not working, should the structures in Collide Against have Colliders?

I have a freelook camera, and added the extension of Cinemachine Collider.
I've set all my structures in the scene into CameraCollider layer, chosen this layer in "Collide Against" option under the Obstacle Detection of the extension, and used the Pull Camera Forward strategy.
(I've also set Near Clip Plane to 0.01 under Lens)
This doesn't work, and camera doesn't move forward when it hits a structure. I'm using Unity 2019.4 and Cinemachine 2.6.3.
Should I add colliders to my structures?
Please help!
Thanks.
I know what's happening, I really need to add colliders to my structures, and the size of the colliders need to be adjusted so they are not so small.
As said in the response, the way to solve this is to add colliders to your structures, and it wouldn't hurt setting those collider's z axis just a bit wider than the graphics

Collider for blender pot model inside Unity

i've made a simple pot model inside blender:
So the idea is that after importing to unity, generating mesh collider, adding ridgin body i would like to be able to put smothing inside the pot. Now it's generating collider but without a "hole" inside, so if i throw smth inside it just bounce off the top. Is there any way to do it simple way? I'd like to avoid making a collider by hand in unity, using cubes and so...
Image overview:
Your collider needs to be concave
It isn't clear from your question how you're "generating mesh collider," but the results are clearly generating a convex collider.
That said, some things to know about mesh colliders (and concave ones even more so): They are very compultationally heavy to calculate, so they should never...
move
scale (especially non-uniformly)
rotate
...at runtime.
Alternatively you can use multiple box colliders in the same orientations as the side-segments of your can (along with one or two for the bottom, depending on how small of an object you'll be dropping inside).
Uncheck the generate collider box from the import settings, add a mesh collider component and check convex.
I would use four or six box colliders for the walls of the pot and another for the floor. You can scale each box collider along each axis, but if you want to rotate a box collider you will need to give it a parent and rotate the parent. Box colliders are very low cost for the physics engine compared to mesh colliders.

Blender to Unity: Add Custom Collider to A Low Poly Style Terrain

I have created a low poly terrain object from Blender using a Plane, displaced and decimated it. I then exported it to Unity as an FBX object. As what I expected, my player simply falls through it since it has no colliders on. I could place a Box Collider on the object, but seeing it is a low poly style terrain with lots of bumps, it'll be pretty awkward to have my player walk straightly even if the ground is slightly raised. Even so, there are mountain areas in my terrain object and box colliders would totally be out of the question.
I was thinking of using the Mesh Collider in Unity. I tried experimenting with it but failed. There are also no clear tutorials online on the said situation. How can I add a custom collider to this terrain so the player can walk to it, plus without using the hastly Box Collider.
Here is my terrain object in Blender:
As you can see, putting a box collider is totally impossible.
You can make individual Sphere, Capsule and Box Colliders, hide their Mesh Renderers and then rotate, scale and place them to make something similar to your mesh. However, Mesh Colliders should be your best option, after adding a mesh collider to your mesh, make sure the convex option is NOT checked and also make sure to select the same mesh that the GameObject is using from the Mesh field in the Mesh Collider component.
Alternatively, if you want your collider to be simpler than your actual mesh, you could make a simpler mesh (either with an external program or by downloading the ProBuilder package in Unity), overlay that mesh with the terrain you have, give it a Mesh Collider and then hide its Mesh Renderer component.
I don't exactly understand what you meant by "I tried experimenting with it but failed." Did your character keep falling through? Did the character get stuck? Was the mesh collider generated in an incorrect way? I would be able to help you better if you can give me a detailed explanation.

How can I make custom 2D polygon in Unity with collision detection?

I am learning Unity and I want to make a little game where the user controls a tank and she can shot with it. My plan is when the missile hit the terrain, it makes a hole in that, like in the old school Worms. My first idea was to make the terrain as a textured polygon and when a collision happens, change the polygon structure. Is it possible to implement this?
You can do a little trick with a 3D mesh. If you are using orthogonal camera the Z axis won't be visible and you will be able to add mesh collider. If you still want to do custom things with that mesh like changing shape there are assets on the store:
http://u3d.as/content/chris-west/mega-fiers/1Qa
Or
When a missle hits terrain change you terrain texture pixels alpha channel to 0
http://docs.unity3d.com/ScriptReference/Texture2D.SetPixels.html
Then use raycasts to check if alpha channel != 0 for moving.

Can a Polygon Collider 2D work with a Mesh Collider in Unity?

EDIT: This is now a rather simple question. I have a 2D sprite that really needs the precision of a polygonal hitbox. The 2D, tile-based world around it uses a tile Mesh for efficiency reasons, and thus has a Mesh Collider.
Before, the tiles in the world were each GameObjects with Box Colliders and Rigidbody 2D's, and the ship and the tiles collided just fine. Now that I am using a Mesh Collider, however, they cannot collide. (I have read that this is because one is 2D and one is 3D.) So what should I do to get collisions (preferably with rigidbody physics) between a polygonal ship and a 2D tile mesh? [end edit]
In a 2D, tile-based, procedurally-generated, chunk-based exploration game (in Unity 4.5), I have a player ship which uses a Rigidbody 2D and a Polygon Collider 2D for collision detection.
This worked fine back when I used a Rigidbody 2D / Box Collider 2D for world tiles. However, this is horribly slow, so I replaced the discrete blocks with a tile mesh, using a Mesh Collider and other associated paraphernalia.
The problem is: I simply cannot get collision detection to work. I have tiles on the x-y plane, and the collision mesh (I can see it in the Scene View, so I know it works) consists of four rectangles perpendicular to the tile. (If you can't visualize this, I don't blame you. See here.)
What have I looked at so far? Well, I verified that the (2D) ship actually passes through the collision boxes in the Scene View. Also, neither of the colliders "Is Trigger".Since there seems to be no official documentation on how to actually use meshes (is there? Where?), I can't find out whether Mesh Colliders and Polygon Colliders actually can interact. Because one is 2D and one is 3D, does this not work? If so, then what should I do instead? I tried using a Box Collider [3D] for the ship, but this didn't work either. I could have potentially made a mistake here, though.
Am I supposed to handle the collision manually (with the OnCollisionEntered [or something] method)? Before, the rigidbody2D objects handled everything automatically. Otherwise, is there any other possible reason the collision might not work?
Well, I'm quite disappointed there seems to be no built-in way to do this in Unity. My solution was to attach a GameObject to the player that would read the block data from the world and create (pooled, of course) real but invisible "collider blocks" with Box Colliders 2D in a small area around the player, such that the player could collide with blocks near them. It works great, and I also implemented an algorithm to spawn rectangular collider blocks over groups of blocks; this eliminates the "ghost pixel" bug in the 2D physics engine.
Uni2D plugin (https://www.assetstore.unity3d.com/en/#!/content/3826) automatically creates 3d colliders (as a group of mesh colliders) from any 2 texture with transparency. A bit expensive but works.