User Manual

Showing the DoD
If the current DoD for a node is different from the frame size of that image, it’s shown in the
tooltip that appears when the pointer hovers over a node in the Node Editor. The DoD is also
visible in the viewer when you right-click in a viewer and choose Region > Show DoD from the
contextual menu.
Setting the DoD Manually in the Node Editor
It is also possible to set the DoD for an image manually using the Tools > Miscellaneous >
Auto Domain node in the Effects Library. This node can be useful when dealing with pre-
created media that does not occupy the full image dimensions. For example, a rendering of a
3D character that walks toward the camera will frequently occupy only a portion of the image.
The Auto Domain node can be used to animate a DoD that covers the character and ignores
the rest of the image, making image processing more efficient.
Region of Interest (RoI)
The Region of Interest, frequently abbreviated to RoI, is a rectangular region similar to the
Domain of Definition. However, unlike the DoD, which tells the node what pixels are actually
present in the image, the RoI tells the node which pixels actually need to be rendered. When a
node renders, it intersects the current RoI with the current DoD to determine what pixels should
be affected.
Enabling RoI Controls
You can turn on the RoI controls to restrict rendering to a small region of the image to
significantly improve performance when you’re only working on a small part of a high-resolution
or complex composition. For example, if you’re using paint to clean up some holes in a matte on
the floor of a composition with many, many high-resolution layers, 3D, and Lighting operations,
you can use the RoI controls to isolate the part of the floor you’re working on, which makes
caching that part of the composition much faster.
To enable the RoI controls, do one of the following:
 Click the RoI button in the 2D Viewer toolbar.
 Right-click in a viewer and choose Region > Show DoD from the contextual menu.
When RoI is enabled and Show is selected from the menu, a rectangular RoI control appears in
the viewer. If this is the first time RoI has been enabled, it will be set to the full width and height
of the image. Otherwise, the last known position of the RoI for that view is used. However, if you
want to set the RoI to a custom area within the frame, you can do one of the following.
To adjust the RoI controls, do one of the following:
 Drag any edge of the RoI rectangle to adjust one side of the RoI.
 Drag a corner to adjust the size of the RoI rectangle from that corner.
 Drag the small circle found at the top left corner of the RoI rectangle to move the RoI
without adjusting its dimensions.
Sometimes, it’s faster to simply draw a rectangle where you want the RoI to be.
To quickly draw the RoI at the desired size:
1 Choose Set from the viewer menu next to the RoI button, or right-click anywhere within
the viewer and choose Region > Set Region.
2 When the pointer turns into an RoI drawing cursor, drag within the viewer to
set a RoI rectangle.
Chapter – 58 Using Viewers 1156