Gizmo Sensors

This code is for Unity engine.

Those sensors use Unity Physics API and they provide Gizmos which work inside Editor - so you can preview what sensors are doing.

Useful for anyone to see in 'real-time' how Raycasting works in Unity.

Types of sensors

LineCast (Physics.Linecast)
BoxCast (Physics.BoxCast)
SphereCast (Physics.SphereCast)
CheckBox (Physics.CheckBox)
CurvedCast (Physics.Linecast - multiple calls)
FullBoxCast (Physics.BoxCastAll)

How do I use this?

Single script (Sensor.cs),

In inspector

Add Sensor.cs to GameObject,

Set "Hit Mask" (LayerMask),

Select sensor type in "Raycast Type",

Change other settings to change shape of your Sensor,

In code

Get reference to Sensor by calling "var s = GetComponent()" or making Sensor s public variable and setting reference to it

Call "s.Scan()" from code whenever you wish to scan,

use "s.Hit" boolean to check if Sensor has hit anything,

FullBoxCast specific - "s.hits" hold all RaycastHits after you call "s.Scan()"

Why is it useful for?

We use LineCast on NPCs for collision avoidance,
FullBoxCast is used as a damage area where NPCs can give damage,
LineCast is used for Foundations (Building) to scan for ground,
LineCast is used for Props placement to scan the surface,
CheckBox is used for all buildable things - to check if there is enough space / volume,
CurvedCast was used for scanning ground by wall-walking NPCs. They were removed out of game now.

How does it work?

OnDrawGizmos() calls Scan() every Editor frame,
some transformation calculations are done,
Gizmos API is used to draw Gizmos,
OnDrawGizmos() is not called when you build your game.
Otherwise, inside game there are never calls to Scan() function. Sensor is static - has no Update() function.

Possible drawbacks

Sensors are not sensitive to scale of Transform. So if you plan to scale your prefabs, sensors will not,
Sensors ignore colliders marked as "Triggers",
Many Sensors will make your Scene view (inside Editor) lag. Rename "OnDrawGizmos()" to "OnDrawGizmosSelected()" - it will draw gizmos only on currently selected prefab.

In action

Licence

MIT licence. Full details in licence.txt file.

viliwonka/gizmo-sensors