Anatomy Of Previzion
Lightcraft’s Previzion is a real-time vfx pipeline in one box. The interface for Previzion is designed to encompass what is sometimes complex and cumbersome technical elements and makes it into a series of procedural-based tabs, panes, sliders and inputs.
Like everything Previzion, features and functionalities are subject to change and continually improves.
The basic anatomy of Previzion and some of the terminology to be referred to in this manual are setup as follows:
- Common Elements:
- Viewer Window – Main video window to display scene, key mattes, foreground, scene blends and depth views. These can be selected from the Keying Tab.
- Observer View Controls – This toggle function allows the user to view the loaded scene, camera position and video in perspective to one another as well as the wireframe of their scene.
- Full Screen Button – Toggles full screen for the whole application (Keystroke is “Ctrl + F”).
- Video Output Select – Previzion has the ability to output two full HD-SDI signals. This is what is being output to set. Set it to “None” to gray out output while making drastic scene changes. Set it to “Matte” to output a parallel matte output. Or set it to “Composite” to send the full rendered scene.
- Timecode/Take Monitor – Samples a timecode to monitor the input. The blue “recording light” indicates when a take is being recorded.
- Memory Monitor – Displays the used memory for the loaded scene.
- Sync Frame Viewer – Displays the actual sync rate for which video is being timed to. This number may fluctuate depending on the frame rate.
- Error Lights – These are your best friend when on set. Should there be any input in the wrong frame rate, a missing input, a flaky input, a mismatching sync rate or a scene that is too heavy to load in the given frame rate, then these error lights light up pointing out to a current problem.
- Quit Button – Closes the whole application and adjacent windows.
- Tab Specific Elements:
- Tabs – Previzion’s settings and parameters are distributed between 10 tabs: Tracking, Lens, Stereo, Video, Keying, Garbage Matte, Scene, Color, Takes and System. Each one of these have very specific configurations needed to adjust each setting in Previzion.
- Panels – Each tab has its own set of panels. From Tracker to Add Mix, this is how every setting is categorized in your Tabs.
- Inputs, Sliders, Drop-Down Menus, Configuration Windows – Previzion’s interface has a handful of components to know about:
- Input boxes take in typed numbers and display the current values.
- Sliders allow you to click and drag the slider to adjust values. Sliders in Previzion are demarcated by two tiny opposing arrows right next to an Input box or by a line with a small handle.
- Drop-Down Menus – For selecting specific settings and pre-assigned adjustments, Drop-Down Menus allow you to select things quickly.
- Configuration Windows – For some settings like color pickers, tracker configurations and so on, there are secondary Configuration Windows that open on top of the main Previzion window.
Toggle into Observer View to verify your Sensor to Camera Offset or to look around your scene to familiarize with the set.
This view is denoted by yellow corners around your viewer window. This is also the only way to view Wireframe in Previzion currently.
Press RESET to position the Observer View Camera on top of the virtual camera as a way to find a starting point from which to look at the scene.
Full Screen Mode
As opposed to maximize, full screen uses the entire real-estate of your screen to dedicate to Previzion, avoiding distracting top bars and Start Bars.
The Keystroke for this is feature is Ctrl + F.
Video Output Select
Previzion default HD-SDI Video Output Select is Composite for Output 1 and None for Output 2. Other available views are:
- Foreground: shows the unchanged incoming live action footage.
- Unspilled: show Foreground with despilled image.
- Matte: shows the current matte.
- Blend: shows the detail extraction image, that will be used to extract fine details.
- Scene Blend: shows the background image with a rough composite of the foreground image, using only the details that will be added during the blend operation.
- Depth: shows a “near-versus-far” display of gradients to represent the virtual depth.
- Composite: shows final composite view.
Sync Warning Lights
The set of red lights highlighted above measure the current status of all incoming data signals.
- Sync Frame Rate Light – checks the rate of incoming data from the Sync Source against the currently selected Video Format, and goes red if they do not match.
- Sync Frame Rate Display Box – The incoming data frame rate is displayed below the Sync Frame Rate Light in the corresponding incoming video frame rate. This is determined by your Sync/Genlock input which may be an analog genlock input or by Previzion’s built-in timer. This value is more accurate than the nominal frame rate value and may fluctuate within a .5 fps range.
- Sync Source Light – indicates when the selected sync input source present is not compatible or missing.
- Location Source Light – indicates when the selected location tracker is not present or has a bad incoming location data.
- Lens Source Light – indicates when the selected lens controller is not present.
- Stereo Source Light – indicated when the selected stereo metadata source is not present.
- Video Source Light – will light up if any of the data sources do not provide a data sample in real time.
- Frame Drop Light – indicates when a scene either has incoming video or video playback in the wrong frame rate. An intermittent blinking indicates a scene that is too much geometry, too many shadders or too many videos playing back. This error light comes on whenever the rendering of each frame is taking longer than the length of a single frame itself at the given frame rate.