Geom Cache

The Geometry Cache component renders mesh data and can play vertex-based animations from Alembic files. With this, you can simulate highly complex geometry effects that might otherwise be unachievable.

Geom Cache Parameters

Use the following parameters to customize your geometry cache.

Geom Cache Parameters

GeometryCacheComponentRequests Interface

This EBus is used to communicate to an entity with a Geometry Cache component. This is available at runtime and at edit time and can be accessed from C++, Lua and ScriptCanvas. Some functionality may be restricted to C++ exclusively.

For more information about using the event bus (EBus) interface, see Working with the Event Bus (EBus) system.

GeometryCacheComponentRequests

GeometryCacheComponentNotifications Interface

This EBus is used to react to events that take place in the Geometry Cache component.

For more information about using the event bus (EBus) interface, see Working with the Event Bus (EBus) system.

GeometryCacheComponentNotifications

The following is a notification bus sample script.

function example:OnActivate()
    self.geometryCacheNotificationHandler = GeomCacheComponentNotificationBus.Connect(self, self.entityId);
end
 
function example:OnPlaybackStart()
    Debug.Log("Playback Started");
end
 
function example:OnDeactivate()
    self.geometryCacheNotificationHandler:Disconnect();
end

The following is a more complete example script of how to use the geometry cache from Lua. See the inline comments for descriptions of what the script is performing at that point.

--Load helpers for handling input events from Lua.
local inputMultiHandler = require('Scripts.Utils.Components.InputUtils')
 
local geomcachetest =
{
    Properties =
    {
        --Specify an existing entity to swap with an existing stand-in
        replacementStandin = {default = EntityId()}
    },
}
 
function geomcachetest:OnActivate()
    --Subscribe to geometry cache notifications on this entity
    self.geometryCacheNotificationHandler = GeomCacheComponentNotificationBus.Connect(self, self.entityId);
 
    --Subscribe to some input events
    --Here it is assumed that 4 events are hooked up to input
    self.inputHandlers = inputMultiHandler.ConnectMultiHandlers{
        [InputEventNotificationId("PlayAnimation")] = {
            OnPressed = function(floatValue) self:PlayAnimation(floatValue) end,
        },
        [InputEventNotificationId("PauseAnimation")] = {
            OnPressed = function(floatValue) self:PauseAnimation(floatValue) end,
        },
        [InputEventNotificationId("StopAnimation")] = {
            OnPressed = function(floatValue) self:StopAnimation(floatValue) end,
        },
        [InputEventNotificationId("ChangeStandin")] = {
            OnPressed = function(floatValue) self:ChangeStandin(floatValue) end,
        },
    }
 
    --An identifier for the stand-in that is currently in use
    --0 indicates no stand-in. See :OnStandinChanged
    self.currentStandin = 0;
end
 
function geomcachetest:OnDeactivate()
    self.geometryCacheNotificationHandler:Disconnect();
end
 
--These events trigger when input is selected
--The first three are simple playback controls. Last one swaps out the stand-in mesh
function geomcachetest:PlayAnimation(value)
     GeometryCacheComponentRequestBus.Event.Play(self.entityId);
end
function geomcachetest:PauseAnimation(value)
     GeometryCacheComponentRequestBus.Event.Pause(self.entityId);
end
function geomcachetest:StopAnimation(value)
     GeometryCacheComponentRequestBus.Event.Stop(self.entityId);
end
 
function geomcachetest:ChangeStandin(value)
     GeometryCacheComponentRequestBus.Event.SetStandIn(self.entityId, self.Properties.replacementStandin);
end
 
--These are the geometry cache notifications
--Emits a simple debug log when events happen
 
function geomcachetest:OnPlaybackStart()
    Debug.Log("GeometryCache: Playback Started");
end
 
function geomcachetest:OnPlaybackPause()
    Debug.Log("GeometryCache: Playback Paused");
end
 
function geomcachetest:OnPlaybackStop()
    Debug.Log("GeometryCache: Playback Stopped");
end
 
function geomcachetest:OnStandinChanged(standinType)
    Debug.Log(string.format("GeometryCache: Changed standin from %d to %d", self.currentStandin, standinType));
    self.currentStandin = standinType;
end
 
return geomcachetest