FIRE can be used as a viewport in the main Maya window or as a floating window. To change a main window panel to use FIRE, go to Panels -> Maxwell, select a camera and then check Interactive Rendering in the same menu. To open a floating window use the FIRE button in the Maxwell shelf. The floating window is the recommended approach, since it provides more options and frees up space for the model panels, attribute editor, channels box etc. in the main window.
The Camera menu in the floating window allows you to select the camera to render. The Viewport menu has the following options:
- Save Image: save the contents of the FIRE viewport to disk.
- Stop: stop the running render.
- Start: if FIRE is stopped, restarts the render. If any changes were made in the scene while FIRE was stopped, they are exported now.
- Full Restart: clears the FIRE scene, exports everything again and restarts rendering.
- Freeze State: stops exporting scene changes to FIRE. The render continues uninterrupted with the current scene state, ignoring further changes. When the box is unchecked, the changes are exported and rendering restarts.
- Allow Selection: clicking on objects in the FIRE viewport selects them. This requires the OpenGL viewport to be rendered behind the FIRE image, so it can negatively impact performance on heavy scenes.
- Show HUD: display UI elements such as camera gate, axis triad etc. over the rendered image. These elements are not saved in the file produced by the Save Image menu command.
- Engine Settings: brings up a window which allows you to configure FIRE options. The settings are the same as those in the Plugin Settings window.
The FIRE window HUD contains several controls linked to the camera exposure attributes to allow you to easily change the current cameras' exposure values. The HUD also contains a start/stop button for quick access to the Start and Stop functions from the Viewport menu and a button to focus the current camera to the current selection.
The FIRE view can be navigated in the same way as a regular Maya viewport, even when in floating window mode. The engine responds to changes in materials, camera settings, environment, geometry, visibility etc. Due to limitations in Maya itself, some complex changes may not be picked up; in that case, use the Full Restart menu command to re-export the scene. Conversely, some seemingly irrelevant changes such as opening a settings panel may sometimes trigger a render restart; unfortunately, these inconveniences are unavoidable at the moment.
Changing the position or geometry of a mesh requires the engine to rebuild its scene representation, a process called revoxelization. This can take a significant amount of time in scenes with heavy geometry, so it is not recommended to use FIRE during modeling or scene layout. The preview engine is designed to allow quick material, camera and environment setup.
Motion blur is currently not supported in FIRE inside Maya.