Preproduction happens before the cameras actually start shooting. During the pre-production stage, the team will organise what is going to happen, do R&D with software and get it all set up to work with the film they aim to create.
During the pre-production stage, low-poly versions of a scene will be created and roughly animated to experiment with what will and won’t work – it’s better to find out which parts of the film are not very good early on than after 6 months of animating because that would be a waste. This is known as a pre-vis.
Various assets will also begin production, mainly ‘Hero Assets’ – models that will be featured constantly throughout the film and take up a lot of screen space. These models will have the most detail and take the longest to create, so it’s best to start them as early on as possible.
The production stage is when material is actually gathered on set for use. Material that is gathered includes raw image footage of the actors, along with reference images of the location.
Grey/Chromeball references are also taken during the production stage. These help get the lighting in a scene as accurate as possible when working in various pieces of software. This is done by placing the ball in a scene and taking photos of it, then recreating the same scene in a 3d program also with the balls in the same location. If the balls are exactly the same in both the 3d and real life scene, you know you’ve got the lighting correct. The chrome side of the ball can be used for HDRi.
During the production stage, lidar scans are used to create 3d recreations of sets or locations with great accuracy. Lidar stands for Light Detection and Ranging, and works by putting out a pulse that bounces off surfaces and back to the sensor. The time it takes to return calculates the distance. What is created is known as a point cloud, a densely packed group of points in space which show the layout of the scene.
3d models which are not Hero Assets also starts at this stage because they will take quite a long time to make, not as long as hero assets but are still vital so lots of time should be allocated to these so they’re ready for post-production.
Now that the footage has been taken from the set, Post-Production can now begin.
One of the first things to do is to match move scenes – make a low poly 3d recreation move in exactly the same way. Once that’s done, you know that anything you place in the scene will move correctly.
The models which were created before can now be rigged, textured and animated.
The clips taken from the Production stage can now be roto’d, edited and composited.
The composition is then look developed to match the feel of the film, and post effects are added.
All elements are then rendered.