Interaction Engine 0.3.1 Interaction between Objects

[nsgn]

After updating to the new system, we are facing a problem with the new layer dependent system. When grasping an object it changes the tag of an object and all childed objects. We want objects to pass between each other. This means that we cannot use isTrigger, cannot use a third layer, and cannot use new interaction material with a custom layer settings. This means that we can't have objects that pass between eachother and have the ability to talk between objects.

For example, we want an object to be spawned, grasped and moved onto another object; this would call a function on the other object changing interaction for it.

What would be a suggested way to have brush hand interaction, interobject communication, and kinematic movement?

[nbenson]

Sounds like your problem might be solved if you could grab triggers! You can enable grasping triggers by allowing trigger colliders to be processed as active by the ActivityManager, which feeds objects into the grab classifier for further processing.

Change line 277 in ActivityManager.cs from QueryTriggerInteraction.Ignore to QueryTriggerInteraction.Collide. Then you should be able to change the grasped object's collider to a trigger, but you'll still be able to grasp it.

There's an update coming to the Interaction Engine that will allow grasping triggers by default, so hopefully we'll have better support for you in the future.

Let me know if you still have issues and I'm sure we can find a solution.

[nsgn]

Thanks, will try on Wednesday!

[nsgn]

Sounds like your problem might be solved if you could grab triggers

It seems that when I use that it doesn't quite work due to the layer change that the hands apply when grasping. It places them on the interaction layer that does not collide with itself, therefore the isTrigger call never happens. I tried using OnGraspEndEvent to force it back into the layer that isTrigger works, but that is called before the last updateLayer() call so it does not help. Any more ideas?

[nbenson]

Have you configured your layers manually? The InteractionNoClip layer is the layer that objects are moved to when they are grasped, but the only restriction imposed by the Interaction Engine is that the InteractionNoClip layer doesn't collide with the Brush Hands layer; it is perfectly valid for the InteractionNoClip layer to collide with itself, which may also address your issue here.

If your InteractionNoClip layer needs to not collide with itself for other reasons in your application, you could also get around your problem by manually querying the physics engine for collisions between the objects you're interested in. I can help lead you in the right direction there if you think that's going to be necessary.

[nbenson]

Another important thing you should check is the "Collision action matrix" at the bottom of Unity's documentation page on Colliders:
https://docs.unity3d.com/Manual/CollidersOverview.html

Specifically, you should check if the Collision or Trigger callbacks you're trying to receive are valid for the two colliders you're trying to detect overlap on. If you see a 'Y' in the appropriate cell, then you're fine, but if you don't, you may need to check for collisions manually. (Again, post back here and I can point you in the right direction for that.)

[nsgn]

Solved it with a new interaction material that uses a seperate layer for the noclipinteraction layer. This means when you are holding an object with that material it will send triggers to our base interaction layer. Thanks for the help! I think that this will work for all cases that we need.

[nbenson]

Great! Thanks for responding back with how you resolved your issue. It's good to know that feature helped.

[nsgn]

I've run into an issue where the object sometimes jumps away from the hand as you approach the object. Any ideas for that?

[nbenson]

Hard to know without more information.

The activity manager will awaken interaction objects that are near the hand; you can check to see if the activity manager waking up the object is responsible for this behavior by modifying the activity radius in the Interaction Manager and seeing if that has an effect on when the object is "jumping away".