Monday, July 6, 2009

#0007 CG Supervisor's Shot Breakdown, Part 1 - Estimate Methods

When it comes to preparing efficient and effective shot breakdowns, the CG Supervisor needs to select the approach most appropriate to the situation.

Several factors effect what kind of shot breakdown you will prepare: time constraints, remuneration, audience, breakdown objective, scale of project, and information available.

Kinds of breakdowns you might prepare include the ballpark estimate, sampled estimate, production budget, resource analysis and each of these could be submitted either in detail, summary or both.

When estimating costs in the breakdown CG supervisors will use widget counting, classification by shot difficulty, classification by shot attributes and combination methods.

Cost Estimation Options
Widget Counting
Widget counting is a way of estimating costs for any given shot by decomposing the shot into a detailed analysis of the work to be done. If you plan to do this, you need to spend time developing a template spreadsheet listing all the possible services or work you would provide.
You then, for each shot tabulate how many of each kind of widget, and then sum all the shots.

For example, your Modeling section could consist of Stock Models, In-house Library models, simple models, average complexity models, high complexity models, mechanical models, organic models, etc. Each of these types of models is then assigned a labor cost, and as you analyze the shot you would mark down how many of each are needed. If the models are going to be used in multiple shots, you might break them out as modeling overhead, so that no single shot has to carry the modeling cost. If models are used in selected scenes, you might have a scene overhead, so that later if that scene is cut, all the costs associated with it disappear.

As you go, each decision will cause cascade effects. For example, an organic model implies a rig and skinning and probably some texture preparation and special shaders. A rig implies character animation. A sophisticated spreadsheet would thus focus in on characters, mechanicals, static props and the like and when these are counted, the appropriate fields for modeling, rigging, texturing, animation, etc are completed.

Widget counting is advisable when working with very tight budgets and effective when the shot count is low, because analyzing a shot at this level takes considerable time. For this reason many CG supervisors and producers employ shot classification.

Classification by Shot Difficulty
Classification by shot difficulty is an extremely fast way to develop a ballpark estimate for shot costs. It cannot be used to give any accurate estimate, but, when dealing with large volumes of shots with similar but not identical production requirements, can be effective enough when one can expect to recapture cost overruns on any given shot by managing the entire volume.

A typical scenario is to classify shots on three levels of difficulty, for example, A, B, and C. This allows a relatively subjective approach where estimators rank a shot's difficulty based on factors such as length, complexity of effects, and complexity of cleanup and roto work. Because it's subjective, it's a good approach when a team of supervisors and producers are looking at an offline edit of a bunch of shots. Everyone gives a ranking and the producer or supervisor doing the actual paperwork writes down the concensus. A numerical approach could also be used, like judges scoring an Olympics event, and the average score becomes the shot difficulty ranking.

Clearly, this is an imprecise method. But, if you need to go through 50 shots at the end of the day when your exempt staff is tired and wants to get home, this is an efficient way to ballpark the work. Just remember to qualify the estimate as a ballpark or rough estimate and if possible, avoid getting locked into a contractual figure. IF a contract needs to be prepared, add a large contingency, anywhere from 10% to 300% percent, based on your confidence in the process and your experience producing similar material.

Classification by Shot Attributes
Classification by shot attributes attempts to find a middle ground between counting widgets and rating difficulty. In this method, an individual or team classifies shots by what work is involved, without necessarily quantifying that work. For example, some shots have roto, but not all. Some have 3d, some have motion tracking in comp and some need it in 3d space. Some have major matte work, some have dynamic effects, some have characters. And so on.

A spreadsheet like this could list the shots in a column and have check boxes for each service. Each service can be assigned a cost value or a cost value can be assigned based on the quantity of services.

Combination Approaches to Estimation
Looking at the two classification methods, classification by attribute and classification by difficulty, it is easy to see how the two methods could be combined to get a modified widget counting approach.

Suppose you took your attribute classification spreadsheet and instead of simply marking each service area on or off, you were to give each service area a difficulty ranking or labor-effort ranking. Then each service could be multiplied by it's labor effort and factored against a rate for that labor. The result is you have an estimate of labor hours and a cost estimate. Because you are not trying to count how many widgets are in each shot, the ranking can be done fairly quickly. Because you've broken it down by service, you have a labor estimate by service that can be plugged into your staffing plan. And because you've put more effort into quantifying your estimate, it is more accurate than either of the simpler classification methods.

Approaches to Cost Estimation
Generally, these are the main ways you can look at a shot to estimate it's costs: widget counting, difficulty ranking, attribute classification and difficulty ranked attribute classification. With some imagination, or further research into general production management, you may come up with another method you like.

Whatever approach you use when estimating costs in a shot breakdown, you will need to consider the factors of time constraints, remuneration, audience, breakdown objective, scale of project, and information available. The important thing to remember is that not every cost estimation method will be appropriate in every situation.

In my next post I will explore this further. Thanks for tuning in.

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