Layer Stacking; Layer = Texture + Object; Effects And Transitions - PRG MBOX User Manual

Layer Stacking

The playback layers of Mbox are rendered in a specific order in regard to "layer stacking." The lowest-numbered layer,
layer 1, is rendered first followed in succession by the higher-numbered layers. This means that lower-numbered layers
may be obscured by higher-numbered layers depending on layer position, scale, opacity, and other factors.
The layer stacking order in Mbox is fixed and unless a 3D object is used on a layer, the layer is considered to be a
"background." If an object is used on a layer, that layer may be moved backwards and forwards along the Z axis in 3D
space, allowing it to be moved in front of 3D objects on other layers. However, 3D objects cannot be moved behind
layers that are acting as backgrounds, and likewise layers that are backgrounds cannot be moved in front of 3D objects.
If a layer is acting as a background and it becomes necessary to move it along the Z axis to place it in front of an object,
then the layer must have an object selected. There are various ways of creating planar objects for such purposes.

Layer = Texture + Object

Each of the playback layers incorporates both Texture (2D) and Object (3D) functionality. The Texture element
displays 2D elements such as still images and movies. The Object element displays 3D objects or digital gobos. The
combination of the Texture and Object elements make up the final composition of each layer.

Effects and Transitions

Mbox Rendering Environment
Mbox loads each layer's raw imagery frame-by-frame onto an individual rendering context. After a frame of imagery has
been loaded onto the context, applying an effect and/or transition can modify it. Layer effects are applied in sequential
order, with Effect 2 being applied to the result of Effect 1 and so on. Transitions are applied at the final point in layer
rendering as a mix between the outgoing and incoming content. All layers are then composited into a single context
called the Global Surface, using the stacking order explained above, and then individual outputs are generated from
designated areas of the Global Surface.
Effects
There are two types of effects in Mbox - Shaders (1-220) and Object Effects (221 and above). Both the shaders and
object effects are available to be used on layers, but only the shaders work on output masters.
Shaders
When applied to a layer, Shaders only work within the original pixel boundaries of the content that has been selected
on the layer. This means that a layer's shader-based effect cannot modify pixels on other layers, or beyond the original
boundaries of the content. Therefore, the result of the shader will only be visible on content on that layer. As a result,
some shader-based effects (e.g. wobble) will appear to have an invisible cropping frame around them.
+ When applied to the Master, shaders work within the boundaries of the entire screen and will affect everything visible
on the screen.
+ Shaders are written as mathematical expressions that modify the properties of individual pixels in the source content.
There are three basic manipulations (with infinite possibilities) that shaders can make: color, opacity, and position.
+ Shaders can be created by anyone and compiled for use on the Mac platform. They can then be imported for use
with Mbox.
MBOX® USER MANUAL
7