View source for GroundCollisionDetection

[[Category:Tutorial]]
[[Category:Tutorial:Avatar]]
In order to detect when a character is on the ground to [[driving|drive]] some action further down the line here is how you can do this in two different ways.

We are going to take the example of driving a Blendshape change, in this case, this Blendshape controls the wings of the avatar. When the [[avatar]] is on the ground, the wings will retract, when it is flying (or jumping) they will expand.

==ProtoFlux Based==
To do this in ProtoFlux we need to extract the Source Node for the CurrentOnGround value in the [[VRIKAvatar (Component)|VRIKAvatar]] component situated at the Root of the [[avatar]].

In this monster of a component, find the ''CurrentOnGround'' value (Under Gaits (list) and above Body Nodes). This value is True if the feet collide with a ground object, and false if they don't. Then we need to convert this [[Type:Bool|bool]] to a [[Type:Float|float]] between 0-1, we can use the [[Zero One (ProtoFlux)|0/1]] Node.

We also want to smooth this transition so that the Blendshape goes smoothly from 0 to 1, so we use a [[Value Smooth Lerp (ProtoFlux)|Value Smooth Lerp<float>]] Node, and we plug in a speed. Finally, we plug this value onto the Blendshape's [[Value Field Drive (ProtoFlux)|Value Field Drive<float>]] Node which we extract from the object we need to drive. 

The final setup will look like this:

[[File:FluxOnGround.png|alt=ProtoFlux Nodes for the ground collision detection driving a shape key|500x500px| [[ProtoFlux Node]] tree for the ground collision detection driving a shape key]]

==Component based==
But we don't need any [[ProtoFlux]] to do this, and we can instead use [[Components]]. First create a new empty object (or place them in an object inside your character) and parent this empty object under your character (you can also reset it's transform so that it's centered with your character and isn't flying around. 

Then we will need three components: [[ValueCopy (Component)|ValueCopy<bool>]] so that we can copy the state of ''CurrentOnGround'' to the next component [[BooleanValueDriver (Component)|BooleanValueDriver<float>]] which we use to convert the [[Type:Bool|bool]] to a [[Types:Float|float]] between 0 and 1 [[SmoothValue(Component)|SmoothValue<float>]] which takes the converted [[Types:Float|float]] and outputs the smooth lerp onto the Blendshape. 

The base setup looks like this.

[[File:ComponentsOnGround.png|765x765px| Initial state of component based for the ground collision detection driving a shape key]]

Then you need to plug the different elements in as follows:

[[File:ComponentsOnGround-1.png|765x765px| Explainer of component based for the ground collision detection driving a shape key]]

And it should look something like this at the end:

[[File:ComponentsOnGround-2.png|764x764px| Final state of component based for the ground collision detection driving a shape key]]