how do I create and use custom masks?
Mark Butts
http://www.markbutts.com
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how do I create and use custom masks?
Mark Butts
http://www.markbutts.com
what kind of custom masks?Quote:
Originally Posted by markbutts
what do you want to do?
In version 3- you can turn any movie or image into a mask.
see the visual fx doc.
http://chaldee1.gotadsl.co.uk/~richa...read.php?t=123
But tell me also what kindof thing you want to do please.
I have a projection surface that is built as a 3:4 aspect ratio with a curved top. All the content is created as 4:3 in a 3:4 safe area. This was done becase Catalyst isn't the only thing using this content. My sides are OK but I need to create a mask to handle the curved portion at the top of the screen.
Is this as simple as creating a black mask in photoshop, making the rest of the area white and using the white to transparent color effect?
The screen surfaces were modeled for presentation in 3-D studio max.
Is it possible to somehow extract these measurments from Max to create
essentially scaled mask? If so how?
I would imagine this would use one of my video channels, and since i want to mask everything being output, the mask wants to reside on the topmost video layer.
Mark Butts
http://www.markbutts.com
visual fx 32 does it for me.
Is this what you mean -- see the attached pdf.
there are several other ways of doing this.
This is not an exhaustive answer.
Mark -
1) Create a camera in 3DS Max and place it at the precise location of the projector that you will be using onsite
2) Make the camera angle the same as your raster image from the projector
3) Render the scene with the appropriate scenic items in place. Lighting should be very flat with no shadows.
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
As you already know, it will need to be on Layer 4 in order to mask out other images. You may find that if you are running out of layers for your show, you might want merge your new mask onto your content so that it always is within the content itself.
Give us a call when you start getting into scenery that requires masking but is automated :cool:
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.Quote:
Originally Posted by RGMdddd
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.
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?Quote:
Originally Posted by RGMdddd
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.Quote:
Originally Posted by 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?Quote:
Originally Posted by RGMdddd
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.Quote:
Originally Posted by samsc
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.
Its not processing power thats the problem with greater colour control - its dmx control channels - and useability.Quote:
Originally Posted by RGMdddd
It is actually possible to do these things - its just a colour lookup table or a colour matrix.
If I were to start counting the number of dmx channels required to do what after effects can do - then it would very quickly exceed anything useable or controllable with ease from a current lighting desk.
And the interfaces on lighting desks are not appropriate for doing complex colour correction.
Once you start looking at the complexity of every function like this - I could add 10 parameters or more to almost every single fx - as you would in after effects - it becomes unusable.
Thanks guys. This was the answer I was looking for.
MB
If you have some particular kindof of effect that you would like implemented that only requires a few parameters, then dont hesitate to tell me,Quote:
Originally Posted by markbutts
Addendum to this recently concluded thread:
I'm creating a series of custom masks in an attempt to do an edge blend - well, corner blend really - between two rasters. A combination of orbital heads, ever-changing scenery and amount of content to be generated makes this something I would like to achieve in Catalyst rather than in After Effects, by dedicating Layer 4 specifically for masks.
What I've tried:
Creating still images with a large, smooth gradient as TIFF files with various combinations of true alpha transparency, white-black gradients with additional alpha, and straight (no alpha) white-black gradients.
What I've found:
TIFF with alpha transparency - doesn't show up in the server at all - blank pane.
TIFF white-black w additional alpha - shows up as black.
TIFF white-black, straight - Comes up fine in server as white-black. Color effects applied to it (best: "invert mask 2") work to an extent.
However: color effects drastically shorten and sharpen gradient. A gradient that takes 300 pixels in the orginal image to transition from full black to full white is condensed by the color effects to about 35-50 pixels, which is not sufficiently smooth or large for my corner blend.
In previous versions I used to create a gobo "movie" with a true alpha for this sort of thing. I was hoping to avoid that this time. Any ideas for achieving a smooth gradient with a still image?
__________________
Jake Pinholster
Try using a straight Photoshop file with transparency or PNG.
I personally use as high a resolution as possible and then scale it using scale and aspect to get a smooth mask.
I find with photoshop files that I need to put all colour to black so as to lose the white fringing on masks and drop shadows.
PNG on the other hand has a smooth transition from black to transparent.
I also turn on the black border in Visual FX so I am able to mask outside my created border.
Hope this helps
Cheers
Toby
somewhere in here is the problem of pre-multiplied alpha - or not....
an extra complication. im not even sure about this issue myself - but it certainly affects compositing.
http://www.td-grafik.de/ext/xfrog/alpha/
http://www.gimp.org/docs/plug-in/appendix-alpha.html
sound to me like you didnt successfully save transparency in your tiff file.Quote:
TIFF with alpha transparency - doesn't show up in the server at all - blank pane.
TIFF white-black w additional alpha - shows up as black.
TIFF white-black, straight - Comes up fine in server as white-black. Color effects applied to it (best: "invert mask 2") work to an extent.
there is a second tiff options dialog in photoshop cs when you save a tif.
it has an option 'save transparency'.
i just made a tif with 5 different vertical grads- some transparent some not.
if you load this into a catalyst layer - you will be able to see some of the blocks are transparent.