Realistic Picture Group

“Propelled”

Case Study

Loud Life Productions / Bank of Central Florida

We recently teamed up with Loud Life Productions to assist with their “Propelled” spot for the Bank of Central Florida.

This project presented some fun and interesting challenges. One part of the director’s vision was an underwater shot of a spinning boat propeller. The propeller would kick into gear and stir up clouds of silt and bubbles. To make matters complicated, this shot was to be the second in a series: the first being a live action shot of an actor writing math equations and drawing a propeller in marker on an LED board. The drawn propeller would then transition seamlessly to the “real” propeller. To make matters even more complicated, this first shot was not a simple live action shot, but was to feature the written equations “coming to life”, separating themselves from the board and floating in space.

To achieve this vision, care had to be taken in each part of the production process, and we were invited to supervise the filming on set to ensure the real camera angles would remain consistent for our CG shots.

The final two shots can be seen below:

 

The LED Board

We decided early on to commit to a locked camera perspective. By locking down the camera, we saved ourselves time by eliminating the need for digital matchmoving. We advised the camera crew to film this shot before the actor had actually written anything. This saved us from having to erase the board again (erasing the board was time consuming!). We needed to film the shot with the board clean because the writing had to separate from it. After the actor finished writing, the camera crew captured images of the writing which we could use later for texture extraction; however, in the end we created a lot of the writing ourselves in post production.

The camera was visually placed in 3D, and we created a plane to represent the board. On top of this plane, we placed a number of smaller planes to represent the chunks of writing. Textures were either extracted from our photo reference acquired on set or created. These resulting textures were mapped to the smaller 3D planes and animated.

With our written text thus recreated and brought to life, we were halfway there but still had an issue: the actor is standing in front of the board and should therefore be blocking the text. Thus, we had to separate him from the background of the scene. Because the scene was shot in a dark environment, we opted not to use a greenscreen. In such conditions, the bright green could have reflected onto the subject too much and corrupted the colors. Since this shot was very short, it was easy to simply create a mask by hand.

With all these elements, including a little bit of added bloom to punch up the writing, we arrived at our final shot.

The propeller

It should be noted that the central “propeller” is designed based on Bank of Central Florida’s logo. It was very important to the director’s vision that the propeller we see in the underwater shot match this logo exactly. It was therefore necessary to build a custom 3D model of the propeller that would transition the shots seamlessly. The propeller was modeled based on references of real propellers, but the proportions were ultimately defined by modeling the surfaces directly over the logo.

The bubbles

Possibly the most challenging part of this shot was creating believable bubbles. This process underwent extensive revision. We tried many different approaches, but in the end, we got the best results by generating trailing geometry from the blades of the propeller. This geometry was then fed into a Pyro solver, and art directed further in Houdini’s Dynamics environment. More points were scattered into the resulting fields and further advected with multiple layers of noise.

Spheres were copied to these points, and became the basic bubble mesh. These spheres were then modified further with more noise, converted to volumes to blur them together, remeshed back into polygons, and finally rendered. Finding the right values for all these steps was a long process and required lots of revision, but in the end we were happy with the results.

Using these techniques, we created several layers of bubbles and volumes representing water disturbance and silt. All these elements were rendered out separately using Redshift and finally brought into Adobe After Effects for a final composite.

Conclusion

There are few things in our world that exhibit such complex and interesting behaviors as fluids. Thanks to the procedural nature of Houdini, we were able to attack this challenge in circular passes, starting rough and gradually honing in on believable and dynamic motion.

Staying organized and maintaining clear communication with the director and camera crew was also extremely important. 3D CG gives us a great deal of flexibility and control, but it is always best for these advantages to be applied with a clear plan of action. Coordinating with everyone at Loud Life Productions was easy and enjoyable.

We are excited to have had this opportunity to leverage 3D animation in these unique ways. Because of the strict requirements that the propeller match both the logo and the drawing on the board, it is safe to say that these shots could not have been created using traditional methods. We love to solve these kinds of unique problems and are excited to see what future challenges the Loud Life team can throw at us.

You can see the full Propelled spot here: