custom masks

[samsc]

4) Open the image in Photoshop and turn the areas within your raster that you wish to mask to black and erase all the areas you wish to have Catalyst images appear. Once onsite, you may need to [Transform] your image in Photoshop due to irregularities of the hang, projection location, etc.
5) Save the image with alpha channels and load into Catalyst

If you use visual fx 32 you can use a black and white image - you dont need alpha channels or you dont need to store the alpha in the file.

In this method - the area really does have to be transparent - with no image data there - you have to save your file as a tiff with transparency to make this happen
You have more flexibilty with image file format if you set the areas you want to be transparent to white.
But Using alpha will work as well.

If you need to display an image with alpha - and you need to see what the alpha channel is doing use colour fx 40 thru 47 - these are basically debugging fx for files which are supposed to be transparent or use alpha channels - they dont have much use apart from that.

[RGMdddd]

The only drawback to using the FX is that you need to be very careful as to the projected content you use. Using true transparency - lack of pixel data - you needn't be concerned for greyscale content.

[samsc]

The only drawback to using the FX is that you need to be very careful as to the projected content you use. Using true transparency - lack of pixel data - you needn't be concerned for greyscale content.

you have to make sure your masks are white?
is this what you mean?

Did you see transparency issues?

[samsc]

you have to make sure your masks are white?
is this what you mean?

Did you see transparency issues?

in colour fx 32 - the red channel acts as a softness parameter which crunches the mask and makes it higher contrast -- up to a point.

[RGMdddd]

Pardon me if I am unaware of a feature that i should be using instead, but let's assume for the sake of argument that I have an image with a black background and contains 256 shades of grey to create the part of the image I want projected. Now I lay this image over a very colorful image and apply the [Transparent Blacks] FX. I believe that I will have varying levels of transparency from this effect. Is this correct?
By creating an image with true transparency (TIFF or PSD, for instance) I can always be assured that my images will look the way I intend them to.

[samsc]

Pardon me if I am unaware of a feature that i should be using instead, but let's assume for the sake of argument that I have an image with a black background and contains 256 shades of grey to create the part of the image I want projected. Now I lay this image over a very colorful image and apply the [Transparent Blacks] FX. I believe that I will have varying levels of transparency from this effect. Is this correct?
By creating an image with true transparency (TIFF or PSD, for instance) I can always be assured that my images will look the way I intend them to.

can you draw me an image of what you want?

and how you want this to work?

And the options you are thinking off?

Can you mock me up an image in photoshop and post it here?

Transparent black will turn the grey image into a transparent region - based on the luminosity of the grey.

[RGMdddd]

can you draw me an image of what you want?

and how you want this to work?

And the options you are thinking off?

Can you mock me up an image in photoshop and post it here?

Transparent black will turn the grey image into a transparent region - based on the luminosity of the grey.

Yep, this is exactly what I mean.
I recently created an animation of blowing leaves. The leaves are full color and so run the gamut in terms of being able to "key" one color or another. Generally speaking, I am a firm believer in using the right tool for the job. In another thread regarding color, the poster asked for greater color control and the reply was that it would take a great deal of processing power to do this on the fly. After Effects does it quite well but rarely previews in real time. I would much rather the processing power of the Mac be used at playing back all videos at full speed rather than trying to apply effects best done elsewhere.