Specifies default selection rectangle sizes for the Blowup Region and the Sub Region, and the parameters for setting up a virtual viewport. Virtual viewports are useful for zooming in on camera views.
The rectangular selection region appears when you render with either Blowup or Region selected in the Render Modifier List. You can change the size of the region by dragging its handles.
The Virtual Viewport options let you zoom in on a sub-region of the current viewport, creating a “virtual viewport” in which you can perform all the standard navigation, but in a zoomed-in area. This function works only when you’re using an OpenGL driver. If you’re using the Software Z-Buffer, these controls are disabled.
You can use the Virtual Viewport on any type of viewport, but it’s primarily designed for zooming in on camera views. This lets you perform closeup work, such as tracing, without distorting the relationship between the geometry and a bitmap background. (See Lock Zoom/Pan in the Background Image dialog for similar functionality in orthographic views.)
Because you’re actually zooming the viewport image itself, the viewport label might be hidden from display, but you can still right-click in the upper-left area of the viewport to display the drop-down menu.
The dialog contains spinners for setting the four corners of the region (in pixels), and the following options:
Use Virtual Viewport: Enables the virtual viewport. A reduced image of the viewport appears in the dialog, along with a white zoom rectangle representing the virtual viewport window.
Zoom, X Offset, and Y Offset: Adjusts the size and position of the virtual window. You can also drag the white window anywhere within the image.
The following keyboard shortcuts are available:
Virtual Viewport Toggle: Turns the Virtual Viewport on and off
Virtual Viewport Zoom In/Out: Zooms the Virtual Viewport
Virtual Viewport Pan shortcuts: Pans the Virtual Viewport. You can switch views within the same viewport while maintaining the virtual zoom area.
You can change these shorcuts in the Preferences/Keyboard list.
The camera viewport is converted to a virtual viewport and displays the area of viewport represented by the white rectangle. All viewport navigation methods work the same as usual, except that you’re seeing only the zoomed portion of the viewport.