You can use Unity UI events to directly call methods for simple interactions, rather than building an UdonBehaviour.
However, we've limited what can be called to this list:
Allowed UI Event Targets
Animator
- Play
- PlayInFixedTime
- Rebind
- SetBool
- SetFloat
- SetInteger
- SetTrigger
- ResetTrigger
- speed
AudioSource
- Pause
- Play
- PlayDelayed
- PlayOneShot
- Stop
- UnPause
- bypassEffects
- bypassListenerEffects
- bypassReverbZones
- dopplerLevel
- enabled
- loop
- maxDistance
- rolloffMode
- minDistance
- mute
- pitch
- playOnAwake
- priority
- spatialize
- spread
- time
- volume
AudioDistortionFilter
- decayRatio
- delay
- dryMix
- enabled
- wetMix
AudioEchoFilter
- decayRatio
- delay
- dryMix
- enabled
- wetMix
AudioHighPassFilter
- cutoffFrequency
- enabled
- highpassResonanceQ
AudioLowPassFilter
- cutoffFrequency
- enabled
- lowpassResonanceQ
AudioReverbFilter
- decayHFRatio
- decayTime
- density
- diffusion
- dryLevel
- enabled
- hfReference
- reflectionsDelay
- reflectionsLevel
- reverbDelay
- reverbLevel
- room
- roomHF
- roomLF
AudioReverbZone
- decayHFRatio
- decayTime
- density
- diffusion
- enabled
- HFReference
- LFReference
- maxDistance
- minDistance
- reflections
- reflectionsDelay
- room
- roomHF
- roomLF
Button
- enabled
- interactable
- targetGraphic
Collider
- enabled
- isTrigger
Dropdown
- captionText
- enabled
- interactable
- itemText
- targetGraphic
- template
- value
Image
- alphaHitTestMinimumThreshold
- enabled
- fillAmount
- fillCenter
- fillClockwise
- fillOrigin
- maskable
- preserveAspect
- raycastTarget
- useSpriteMesh
GameObject
- SetActive
InputField
Character limit
Please note that input fields are limited to 16.000 characters, which is the maximum amount of characters a text component can render.
- ForceLabelUpdate
- caretBlinkRate
- caretPosition
- caretWidth
- characterLimit
- customCaretColor
- enabled
- interactable
- readOnly
- selectionAnchorPosition
- text
- textComponent
- selectionFocusPosition
Light
- Reset
- bounceIntensity
- colorTemperature
- cookie
- enabled
- intensity
- range
- shadowBias
- shadowNearPlane
- shadowNormalBias
- shadowStrength
- spotAngle
LineRenderer
- allowOcclusionWhenDynamic
- shadowCastingMode
- enabled
- endWidth
- loop
- motionVectorGenerationMode
- numCapVertices
- numCornerVertices
- probeAnchor
- receiveShadows
- shadowBias
- startWidth
- lightProbeUsage
- useWorldSpace
- widthMultiplier
Mask
- enabled
- showMaskGraphic
MeshRenderer
- shadowCastingMode
- enabled
- probeAnchor
- probeAnchor
- receiveShadows
- lightProbeUsage
ParticleSystem
- Clear
- Emit
- Pause
- Pause
- Play
- Simulate
- Stop
- Stop
- TriggerSubEmitter
- time
- useAutoRandomSeed
ParticleSystemForceField
- endRange
- gravityFocus
- length
- multiplyDragByParticleSize
- multiplyDragByParticleVelocity
- startRange
Projector
- aspectRatio
- enabled
- nearClipPlane
- farClipPlane
- fieldOfView
- orthographic
- orthographicSize
RawImage
- enabled
- maskable
- raycastTarget
RectMask2D
- enabled
Scrollbar
- enabled
- handleRect
- interactable
- numberOfSteps
- size
- targetGraphic
- value
ScrollRect
- content
- decelerationRate
- elasticity
- enabled
- horizontal
- horizontalNormalizedPosition
- horizontalScrollbar
- horizontalScrollbarSpacing
- inertia
- scrollSensitivity
- vertical
- verticalNormalizedPosition
- verticalScrollbar
- verticalScrollbarSpacing
- viewport
Selectable
- enabled
- interactable
- targetGraphic
SkinnedMeshRenderer
- allowOcclusionWhenDynamic
- shadowCastingMode
- enabled
- lightProbeProxyVolumeOverride
- motionVectorGenerationMode
- probeAnchor
- receiveShadows
- rootBone
- skinnedMotionVectors
- updateWhenOffscreen
- lightProbeUsage
Slider
- enabled
- fillRect
- handleRect
- interactable
- maxValue
- minValue
- normalizedValue
- targetGraphic
- value
- wholeNumbers
Text
- alignByGeometry
- enabled
- fontSize
- lineSpacing
- maskable
- raycastTarget
- resizeTextForBestFit
- resizeTextMaxSize
- resizeTextMinSize
- supportRichText
- text
Toggle
- enabled
- group
- interactable
- isOn
- targetGraphic
ToggleGroup
- allowSwitchOff
- enabled
TrailRenderer
- Clear
- allowOcclusionWhenDynamic
- autodestruct
- shadowCastingMode
- enabled
- emitting
- endWidth
- motionVectorGenerationMode
- numCapVertices
- numCornerVertices
- probeAnchor
- receiveShadows
- shadowBias
- startWidth
- lightProbeUsage
- widthMultiplier
UdonBehaviour
- RunProgram
- SendCustomEvent
- Interact