Quick Tracking

Quick Panel

The Quick Autotrack feature in MotionMaster 3D provides a fast way to track your footage using SLAM (Simultaneous Localization and Mapping). When using this method, you get a live preview of the camera solve combined with your footage, showing how features are extracted and how the camera's movement is calculated.

Keep in mind that this method requires knowledge of your camera intrinsics, such as sensor width, focal length, and resolution in both X and Y, in order to accurately solve the camera. It is also helpful if you know the distortion parameters of your lens, but this is not strictly required unless your footage has significant distortion.

With that said, let us go through the Quick panel in detail and explain what each parameter does.

Saved Optics Presets

The first section is the Saved Optics Presets tab. Here you can save your current configuration as a preset for later use by clicking Add preset. To apply an existing preset, open the dropdown menu and select the one you want.

Optics Configuration

The main configuration box is where you define the core intrinsics. You can enter the Focal length (mm) or the Focal length (px), as well as adjust the Sensor width and the footage resolution in X and Y.

These values are linked: for example, if you change the sensor width or resolution, the focal length in pixels will automatically update because these parameters are constrained by a formula. Correct optics settings are crucial for a successful track. Most problems that arise are due to incorrect intrinsics, so make sure these values are accurate. If you notice that almost no features are being extracted, it is likely because the optics settings are incorrect, which results in the wrong focal length in pixels.

Advanced Settings

The advanced settings include the optical centers in X and Y. By default, these are set to half of the resolution values, and they update automatically when the resolution changes. This is intentional, since most users do not need to adjust them manually. However, if you do want to set custom values, first define the resolution, then overwrite the optical centers.

The rest of the fields are for lens distortion values: K1, K2, K3, P1, and P2. In most cases, you can leave these at their defaults unless you know your camera's calibration.

Performance Settings

Performance settings affect how the tracker extracts and matches features. The Number of features controls how many features to look for in each frame. Levels defines how many pyramid levels are used. A pyramid is a set of downscaled copies of each frame, which allows the tracker to find features at different scales (zoomed in or out).

Each level is scaled according to the Scale factor. For example, with a scale factor of 1.20, level 0 is the original image, level 1 is scaled to 1/1.2 of the original size, level 2 to 1/(1.2²), and so on. A smaller scale factor gives finer steps between levels but requires more levels to cover large zoom differences, while a larger scale factor is faster but less precise.

The Init threshold fast sets the primary threshold for the FAST corner detector. It looks for strong, obvious features first. If not enough are found, the tracker falls back to the Min threshold fast, which accepts weaker features. If you are not getting enough features, try increasing the feature count and lowering the threshold values.

Viewer Settings

The Viewer settings control how the live preview window looks. While most users will not need to change these, they can be useful for customizing the display.

You can adjust the keyframe size and keyframe line width to change how keyframes appear, and the graph line width to control the thickness of the motion path. The point size changes how large feature points are displayed. The camera size and camera line width affect how the drawn camera rig looks. Finally, the viewpoint parameters set the default viewer position and focal length, which define the angle and distance from which the tracking scene is shown.

Tracking Direction and Overlap

At the bottom of the panel are the Forward and Backward options, which control the tracking direction. Quick Autotrack is a SLAM-based tracker, meaning it only has access to past frames, not future ones. This allows real-time tracking but also requires an initialization period before it can begin solving the camera. As a result, the first few frames will not have a solved camera position.

For example, in a 100-frame sequence, the tracker might only start solving at frame 20, leaving frames 1 to 19 without a solution. To minimize this gap, try to include parallax movement (camera translation) early in the footage, as this helps the tracker initialize faster.

The Smart overlap feature improves this process by limiting the backward pass to only the region where the forward tracker failed, plus a margin. The margin is controlled by the Overlap setting: Low (factor 2), Medium (factor 3), or High (factor 4).

For example, if the forward pass starts solving at frame 20, the initialization period is 19 frames. With Smart overlap set to Medium, the backward pass will start at approximately frame 77 (20 + 19 × 3) and track backwards to fill the gap. In most cases, you can leave these settings at their defaults.

The collapsible Tips for Best Results box above the Autotrack button sums up what makes footage track well with Quick, such as early camera translation and correct camera data.

Running Autotrack

Once everything is configured, press Autotrack (Quick) to begin. Two windows will appear: one showing the live camera solve and one showing the feature extraction. If both Forward and Backward tracking are enabled, these windows will reopen for the second pass. When the process finishes, you will see the extracted 3D points and a moving camera in your Blender scene.

Focal Length Estimation

The Quick panel also includes a Focal length estimation tool. Set a start frame and an end frame, then press Estimate focal length. The addon will run a short process using the Heavy Autotracker in the background to estimate the focal length from that section of footage.