Camera Tracking 3D Animations

Introduction

One of the biggest advancements in 3D animation is camera tracking. Put simply, it is the process of combining real video footage with 3D animation. The finished result is amazing as the subtle irregularities of reality are picked up perfectly in 3D. A well prepared scene will have 3D additions that aren't noticeable at all.

This kind of special effect used to be restricted to big-budget Hollywood, but now most companies can have access to it.

Shooting the video footage

At Archiform 3D we now use helicopters and High-Definition video cameras the most. Aerial footage is the best way to portray large, unique projects and helicopters give us the flexibility we need to get almost any kind of shot using high-quality equipment.

Advancements in camera technology also means that the typical gyro-stabilized camera mounts are not necessary as the image stabilization in the camera plus our small camera mounted gyroscopes get a shot that is rock steady. Large budget movies can afford to have expensive stabilization pods and even better cameras, but made for TV, corporate or real estate budgets cant stretch that far. We've has always been a specialist in getting maximum value for money, so hand held, in harness shots are 90% of our work.

High-definition video cameras also give us an incredibly clear, sharp image with the resolution we need to accurately process the footage. And to make the process even faster, these cameras interface either directly to our work stations.

While Archiform 3D's rates are fixed we do not include the helicopter costs, so you need to budget them. Helicopters cant be the least expensive ones either - they should preferable be large jet turbine models that don't bounce around and have the power to carry out the maneuvers that we need to get the best shots. For an hour of time in the air your should allow between $800 and $1200.

Tracking the video

Firstly we stabilize the video. This process, while taxing on a workstation, doesn't actually require much human time - just hours of CPU time. All the the bumps and jumps from the footage are removed and the result is silky smooth video. If the shot is god then less stabilization is needed, but if it was taken from a small helicopter or in turbulent weather then more is needed and there is a slight reduction in finished quality.

The actual tracking of the video is partly automated task although still requires a great deal of human time. The simple fact is that it is a very complex process that cannot be done by man or computer alone†. Points in the video are marked and through a process of manual input and automated tracking the computer determines a set of moving 3D coordinates that depict where the camera was at each point in time. As you may imagine, especially if you have a mathematical background, the computational power to determine this and track the points is somewhat huge and would have been next to impossible in the recent past.

The process of tracking a few minutes of video footage can take days, possible weeks, depending on the quality of the shoot and the subject.

Adding the 3D animation

Building the 3D model itself is a different process again, so from this point on we will assume it is done. The camera coordinates are brought into the 3D scene as is the stabilized footage. Then there is another painstaking process, which is aligning the camera and the model with the video background. Even though the footage is tracked the coordinates will not actually relate to the scene until adjustments are made. This may take hours or days to get right.

Then the lighting in the 3D scene needs to be adjusted to match the lighting on the actual day the video was shot. The idea is to get a seamless combination of the model and reality.

Other factors come in to play as well, such as foreground objects in the video. These require a technique called rotoscoping, which is a moving layer of transparency that is added to the final 3D rendered footage to ensure that anything that is supposed to be in front of the building is still there after the 3D footage has been added. Once again this is a computer/human combination that can take some time. Normal rates for Archiform 3D to create camera tracked 3D animations do NOT include rotoscoping and we will shoot to avoid it's need, but if you require it we can do it for an additional fee.

Uses for tracked 3D animations

It is likely you have seen camera tracked 3D animations many times, you just haven't known it. The technique started where all cool 3D techniques come from - Hollywood. The use of 3D has grown so much and the need for virtual sets has also grown. But virtual sets cant always be perfect and the need to blend reality became overwhelming.

For example, imagine you want a scene of travelers on camels riding to the pyramids of egypt but set in BC times. You could build it all in 3D but to get it perfect and have your actors in the scene gets hard and expensive. Camera tracking allows you to use real actors, real camels and real desert, fly over in a helicopter and then add the pyramids, city and people in 3D. You now have a perfect scene that can have your actor somewhere that is real but thousands of years ago.

Archiform 3D has used the technique for new buildings and features. We fly over in a helicopter and then add in the new work so the viewer sees it as though it was complete. If the property has some kind of unique or attractive feature, like a beach, lake, park or great location, then this technique is quite valuable.

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