BCTheaderimage

Friday 18th May 2001

This tutorial is from 2001. Obviously things have moved on a lot since then but its still a good primer for Previz.

Recently the phrase”pre-visualisation”has been used more and more in the effects world. What is it and what exactly is the benefit?

As we have more and more power at our fingertips the temptation is to take on more ambitious and complex projects. Compare the amount of effects shots in a typical movie these days with around 500 effects shots compared to 5 years ago, when 50 or so shots was considered a massive undertaking.

Obviously this leap in the volume of work and consequently the huge increase in the amount of people involved in creating images requires a new way of thinking and planning to ensure the director’s vision is evident in every frame of the movie. In animation terms the pre-vis stage is similar to the animatic.

Even though we’re not all working on projects the size of Star Wars or Titanic. The concept of pre visualisation can prove invaluable, allowing everyone involved (including the client) to understand exactly how the project will look from the start.

As an animator I often use pre-vis to choose the composition, lighting and dynamics of a shot well before I begin a project. This ensures I’ll only model and animate those elements that are required and that they’ll all fit together at the end of the project.

Case study 1, Tanks

Currently I’m working on a short personal project, which involves bringing together 3D animation and live action. Using pre-visualisation allowed me to design and compose the shot quickly at the start of the project. It also allowed me to explain to a crew how to shoot the live elements and serves as a guide for myself throughout the project.

tank1

above Pre-vis of tank scene used as a place holder for composite and for lighting ref.

The result of the pre-visualisation process allows me to have a place holder as my background meaning the compositing and 3D stages can run in parallel, very useful when working on a TVC or short that can’t afford to wait for 3D elements.

Case study 2, Fight Club – Plane Crash

Obviously I didn’t work on Fight Club (although I wish I had!), but the article printed in Cinefex 80 on the movie highlighted the value of the pre-vis stage in saving both time and costs.

fight

above Pre-vis from Fight Club showing how a simple rendering allowed the director to decide how the scene should look before work began. Bottom right you can see the pre-vis even included a shooting diagram to allow the crew to figure out where to place the camera and green screen and which elements would be cg (in orange), practical (blue).

Case study 3, Star Wars Episode I – Pod Race

The pod race sequence in Episode I is nearly 25 minutes long, and every shot involves some very complex compositing and effects work. ILM produced a pre-vis of the entire sequence allowing George Lucas to direct and edit those shots until the sequence was finalised.

Only at this point did ILM start adding high res models, textures and animation this meant no time was wasted creating footage that wouldn’t be used. Without the pre-vis stage it’s unlikely the pod race sequence could have ever been produced given the amount of complexity involved.

Says David Dozoretz of ILM in Cinefex 78 : “We took pre-vis up a notch. One of the unwritten rules of animatic is to keep things rough. You want people judging images for the right things, such as blocking and pacing, not photo realism. But for the sequences like the pod race, we had to be more detailed.”

Interview with David Dozoretz taken from Cinefex Issue 78

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