http://www.posetteforever.com/viewtopic.php?f=1&t=2672&p=35207#p35207
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VK
Thursday, 29 March 2007, 01:44 PM

Re: Cars With Posable Pedals, Steering Wheel - Like The Cobra
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The changing parts are "alternate geometry".

In the figureResFile, the geometry of actors "sparewheel" and "pillion" is a single tiny polygon "p_dummy" inside the Vespa body. The "p_dummy" geometry is invisible. 

[code linenumbers=false]
actor sparewheel:1
	{
	storageOffset 0 0 0
	geomHandlerGeom 13 p_dummy    <---  tiny single polygon 
	}
actor pillion:1
	{
	storageOffset 0 0 0
	geomHandlerGeom 13 p_dummy  
	}
[/code]

There are extra geometries for the pillion, the spare wheel, and the rack to mount the spare wheel. 

In the respective actors, for example "pillion", there is an "alternateGeom" instruction to load the pillion geometry. There is also a "geomChan" channel which displays a dial to choose the alternate geometry. 

[code linenumbers=false]
actor pillion:1
	{
	name    pillion
	on
	bend 0
	dynamicsLock		0
	hidden		0
	addToMenu	1
	castsShadow		1
	includeInDepthCue		1
	parent vespabody:1
	alternateGeom    pillion
		{
		name pillion
		objFile 1003 :Runtime:Geometries:vspscooter:pillion3.obj    <--- the alternate geometry
		}
	channels
		{
		geomChan pillion  <--- choose alternate geometry
			{
			uniqueInterp
			name (pillion)
			initValue 0
			hidden 1
			forceLimits 4
			min 0
			max 1
			trackingScale 0.045
			keys
				{
				static  1
				k  0  0
				}
			interpStyleLocked 1
			staticValue 0
			valueOpDeltaAdd   <---   ERC slave code
				Figure 1
				BODY:1
				vpvsp3pillion
			deltaAddDelta 1.000000
			}
		}
[/code]

The geomChan channel is an ERC-slave of a master channel in BODY. When you set the master, the geomChan loads and displays the alternate geometry, for example the pillion.

[code linenumbers=false]
actor BODY:
	{
		{
		valueParm vpvsp3pillion    <--- ERC master
			{
			name Pillion
			initValue 0
			hidden 0
			forceLimits 4
			min 0
			max 1
			trackingScale 2
			keys
				{
				static  0
				k  0  0
				}
			interpStyleLocked 1
			}
[/code]

You find more information on alternateGeom and ERC in the ERC tutorial, Chapter 9.
(www.atlantis23.com/erc_download.html).