I'm currently following the the book Maya Studio Projects: Dynamics and find I'm fumbling through it. I've been able to work my way through some of the miss printings - although I'm only on the second project.
This is where I get stuck... I'm working on getting particles to come out of a comet in orbit. In one of the steps, I add an rgbPP and create a color ramp. No problem. But the directions then read "Use the particle's age for the Input V." That's it. Doesn't say anything about what or where input V is nor how to use the age for that value. I set the colors on the ramp correctly, and everything "LOOKS" right when it plays, but I've done nothing that I know of to set an age for input V.
Maybe I'm just misunderstanding something, and some simple guidance can clear this up. If anyone has this book, i'm on page 9, step 3.
When you map a ramp to a per-particle attribute like rgbPP, Maya automatically creates a few in-between nodes for you. One of these nodes is called an 'Array Mapper.' This is the node that checks some property of the particle, then looks at the ramp to determine what value to pull from it, then hands that value back to the particle.
When you right-click on a per-particle attribute and select 'Create Ramp,' you have the option of just executing that command with default settings, or of clicking on the options box to specify settings. In this case you probably just used the default settings, which work fine, but that's why you missed seeing the option in question.
Next time, try right clicking on the per-particle attribute and selecting the options box next to 'Create Ramp.' You should get a little options window popping up, asking you what particle properties to connect to the ramp, whether you want to use an existing ramp or create a new one, etc. That's most likely what you were missing.
In most simple cases, you'll want to use the particle's age to drive the ramp, which is the default connection anyway, so you won't often need to use this window.