Attached Link: http://members.home.net/nuke-m/

Someone asked how to mask out a Poser figure so it could pass in front of and behind certain objects on an animated .avi file. JeffH suggested rendering the sequence out to individual image files (frame by frame) and editing them in a paint program and then moving elements to different layers in order to float them in front of, or behind the figure. I'd just like to add to Jeff's suggestion: Create a *travelling matte* for any objects that are in the foreground or mid-ground. I.e. objects that the character can pass in front of and/or behind but aren't part of the base background. Now, there are probably easier and faster ways of doing this by using expensive post production software. But this method I'm about to explain only requires you to have 3 software packages: a 2d graphics app, Poser (of course) and a utility that compiles separate images into an animation file, like an .avi file or something. This is the 'dirt cheap' style! :-) **How to do it:** 1) Render each object's sequence in Poser as you would normally - with full textures and lighting etc. 2) Render the *same* sequence again except make the following changes: 2a) Change your Document Display Style to "Silhouette" and turn off "Ground Shadows" 2b) Change your background colour to something that completely contrasts the figure's silhouette colour. E.g. white figure on black background or whatever. Under "Render Options," go to the "Render Over" box and turn on the "Background Colour" option. 2c) Under the "Make Movie" menu in Poser, change the Quality to "Current Display Settings." Then render out your frames. This will create the travelling matte for your fully rendered frames. 3) Find the frames in your sequence where the character is supposed to go behind or in front of a particular object. In a 2d graphics app that supports multiple layers, apply the magic wand selection tool to the *matte layer* that corresponds to that frame. This will generate a highly accurate selection. Using this newly generated selection, flip to the layer with your figure in it and cut the figure out and float it in front of, or behind the object as you desire. 4) Save the frame in the desired image format. It's a good idea to keep all final composited production frames complete separate from your draft frames. E.g. Create a new directory and put them in there.

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Why do all this? For several good reasons: It's a time saver. If you use a paint program with a "magic wand" style selection tool (e.g. Photoshop, Paintshop Pro etc) you can instantly create sharp and accurate selections of your objects simply by applying the magic want to the matte. This saves you time because you don't have to manually trace and cut your figure out of a full colour rendered frame. This can be really time consuming, especially if you have several hundred frames to do. :-) TIP: You can use Photoshop's action recording capability to automate the process of creating a matte-based selection and applying it to its correspnding frame, and then pasting it onto the background frame. You can then batch process large numbers of frames easily. Instant alpha channeling of frames If you convert your mattes to grey scale images, you can load them as alpha (aka transparency) channels and apply them straight to your frame. Adobe Photoshop and Paintshop Pro both support alpha channeling in this manner. This enables you to instantly specify areas of a frame to range from being completely opaque to completely transparent. Works like Poser's transparency maps except in a 2D fashion: Whatever is black is totally transparent. Whatever is white is totally opaque. And the greys in between determine the level of transparency. This gives you many possibilities! Flexibility By generating your frames in this manner, you have the ability to make changes on the fly or to apply special visual effects to your frames without having to re-render whole sequences. It could all be done in post-production. Doesn't require you to have a super computer of a set-up at home. ...enough said. :-) - - - - - -

You can do nifty things like applying one of Photoshop's plug-ins to a frame's matte, then making a selection based on that. Or applying a plug-in's effects across a number of animation frames using Photoshop's batch action features. You can try all sorts of neat things. - - - - - -

CAVEATS: Make sure the matte frame is exactly the same size as the full rendered frame. This removes any need to manually position any selections generated by using the matte frame. This, in turn, will make it much easier to batch process frames using Photoshop's batch actino features. Plan your shots carefully and work in a systematic fashion and keep your files organized! These travelling mattes will generate a lot of image files. Things can get confusing quickly if you're not careful. Use filenaming conventions and separate directories to help you out. You may not be Spielberg or Lucas, but you're still making a movie. And big or small, planning your movie's shots out carefully and beforehand is a must. Draw out a storyboard, no matter how crude. This'll enable you to foresee any potential problems. It'll also give you a better idea of what you'll need and how to go about making certain shots. This technique doesn't really work for objects that must interact with each other on some level. E.g. If you need on object to cast its shadow on another, or if you need one object to be seen in the reflective surface of another object.... But this is where the pre-planning/storyboarding stage comes into play. If you know beforehand which objects need to interact with each other on this level, then you'll know which objects need to be rendered together in the same scene within Poser, and which objects can be done separately and matted in later. And, like I said at the beginning--- this is the cheap and dirty method of digitally compositing objects in your animation. There are sub-pro and pro level post-production packages that handle this sort of thing better and more efficiently. But, unless you've got access to a post-production studio and its software and the training to use them, then your options are rather limited. This method takes advantage of software packages you probably already own... BTW, the same techniques can be applied to rendering still images too. If, like me, you don't have the memory to put hundreds of spaceships into a single space scene all at once, then you have to render them separately or in smaller groups and composite them later in post production. I hope this helps or, at the very least, gives you some nifty ideas for things to try... Nuke If anyone's interested, I can clarify a few things by creating a tutorial on my web page...

nukem - WOW... great posting, and many thanks for all the excellent tips here ;-) I`ll be saving this out as a seperate document for future reference. Certainly like the idea of applying Photoshop filters to a range of frames with the batch process...! Any tutorials you are kind enough to make will be most welcome by a large number of folks, I suspect. Thanks again.

Hi, Polartech Glad you found it helpful! :-) I typed it out late last night after a glass of wine. I don't normally drink alcohol, not even beer, so I may have made a few boo-boos. ;-) Yes, I'll create a tutorial for this but it probably won't be up until a week into 2001. I want to do further testing of a few ideas, and if possible, see if there's any streamlining that can be done. I've also got a few modelling projects due for some people here so once I've completed them, I can get started on the tutorial. Nuke