UE4/Collisions

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UE4-logo-g.png

(last edit version: v0.4.0)


Particles <==> World Collisions

The UE4 PopcornFX plugin is in charge of handling world raycast queries, mostly used by:


World Interaction Mode: One or Two Way

The physics evolver World Interaction Mode defines how the particles will interact with the World.

  • OneWay collisions: particles simply collides against the world
  • TwoWay collisions: OnWay collisions + particles can inject physics into world, eg: add impulse to objects they collide.


The particles and rigidbody's Mass is what drives the strength of the interaction.


Ue-collisions-twoway.jpg Ue-collisions-twoway-2.jpg


Collision filters

Use collisions filter to filter out Collisions Channels globaly or for specific FilterID.


Contact materials

You can drive the particles collisions restitution/bounciness by using different Physical materials on colliding surface.

Please refer to Unreal engine 4 documentation to properly setup your physical materials.


Ue-collisions-contact-material.jpg Ue-collisions-contact-material-2.jpg Ue-collisions-contact-material-3.jpg


Note:

  • Collision restitution/bounciness is defined by FinalRestitution = PhysicsEvolver.Restitution * PhysicalMaterial.Restitution.
  • Collision friction is not implemented yet.
  • Physical material interactions are disabled by default, make sure bEnablePhysicalMaterials on the PopcornFXScene is enabled.
  • UE4's default material restitution is 0.3