Re: Switiching Betweeen Keyers

Hi,

No need to apologize. That is exactly what this forum is for.

From what you describe, it sounds like a good approach might be to do a rough rotoshape to mask the area you want a particular keying node to affect and plug that into the keyer's mask input (on the side of the node). There is no need to use a switch node if you animate the rotoshape to follow the area you want to affect. (Obviously if a switch helps you do what you need, then use it, but I don't think it is necessary.)

You can then combine the keys into one mask with various layer nodes, eventually applying it to your footage with the switchmatte node.

Before you get to the switchmatte, you may want to use a dilate/erode filter followed by a blur to soften the edge. Are you biting into the matte in the keyer node? I don't know if this would give you more or less control than the dilate/erode node placed after the keyer. It might be useful to experiment with both approaches.

My feeling is that the best way to approach keying is to think of the keying node as only the first step in creating a mask. You then use a number of other nodes to modify exactly what that key does. I usually end up using a lot of shiftchannel [I forget what it's really called] nodes to put the alpha into the red channel so I can use brightness/contrast nodes on them. Also it can be helpful to place a saturation node above your keyer and push the color saturation up high so the keyer has more color contrast to work with. This results in a rough key, but with a lot of tweaking down the line and combinations with other keys, it can have its uses.

I hope this helps,

Lars

Lars Jagatai Bunch
lars@larsbunch.com
www.larsbunch.com