Picture Mattes

Since nearly the beginning of filmmaking, a discovery has been made that we can use filters to block out certain colors from film in order to layer something behind it, using multiple exposures through a procedure called Optical Printing -  A process that we've all come to know as "Blue Screen". This works because most things shot in film are never quite That Blue on film - so it was one of the great choices of color. But in truth it doesn't have to be blue at all. The new common color of choice for this has become Green. 

PD Howler offers blue screen, green screen, as well as Magic Pink (magenta) as base color mattes but in the end, we can actually use any color we like as our key. These just make the job easier as they tend to Stand Out from most other colors in our average image.

​Another way to superimpose one image over another is through the use of Mattes.

For film - before the digital era, these mattes are a black shape on transparency to hold light back from being captured on the film for that particular frame.

In the digital world, this is what we refer to as the Alpha channel of an 8 bit image. Some software, like Photoshop and Fusion, can isolate that alpha information and use it as an individual matte for anything, if we want to. Because in all actuality, the alpha channel is simply matte information collected as grayscale data that is isolated to its own channel within the image data.

DAZ Studio's Iray render engine can produce very nice alpha information - making our job in post so simple that we just don't need to worry about "How to use Mattes" in post - we can simply stack our renders in whatever order we wish to achieve the look we want in the end without even giving it another thought. 

In truth, however, we're using a process that used to have to be done by hand by a Matte Artist for every frame that needed alpha! It's really nice being spoiled, isn't it?!!!

In the below image, notice how shadows are spilling onto the floor slightly beyond the matted-out wall (lower left). Later in the shot, Catcher Plus (see below) also captures reflections from the gunfire of her blaster against that matte wall, making it much easier for us to create a believable shot using nearly any background.

PD Howler gives us amazing opportunities for creating our own brushes on the fly. In fact, it was truly developed around the idea of using brush mattes for many, or even most of everything we do in Project Dogwaffle. Work out an image, making it into a brush, and paint with it - either in still form or across an animated filmstrip. 

The Magic of Catcher Plus!

Catcher Plus, by 3D Universe allows us to lay down mattes directly in the scene. The most common practice of this being applied to a plane, and then we place the plane anywhere we want to 'matte out' part of what would otherwise be rendered as part of the image.

It will even create a plane for us, if we ask it to! :)

With Catcher Plus applied to any geometry, we're able to block out parts of the image to the Alpha channel in exactly the same way as having an Alpha floor or ground - allowing us to superimpose our renders over any background we choose.

In this example, I'm using Catcher Plus to catch the shadows and mild, muted reflections from Rosie who is using a cube as a wall to provide cover from incoming fire as she blasts her way to freedom. Notice how she can hide behind it, and as it turns out, what she's hiding behind becomes truly invisible. An Instant Hole, if you will. Then, when she steps out and fires her blaster, the reflections and shadows get collected onto the invisible surface.

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