Virtual CRASH Camera Tracker
Camera position and orientation against time, from tracked video features and one calibrated frame.
project settings
Sets the length and speed units together for every figure below. Angles are in degrees either way.
calibrated frames
Calibrate the camera in Virtual CRASH on one frame of the video, then paste the report for that camera here, from its name down through its calibration lines. A report may hold several calibrated cameras, each calibrated on a different frame of the same video. Every camera found is listed in the table below, where its values can be checked or edited.
Enter t_c for each camera: the video time of the frame it was calibrated on, which must lie within the tracked interval. It is taken to the nearest video frame. The first camera needs at least four tracks with a point in its frame or running through it, preferably six or more, since the solution is built outward from it.
| Use | Camera | t_c (s) | x | y | z | Yaw | Pitch | Roll |
|---|
Weighted lets each calibration move within its stated accuracy to agree with the tracks and with the other calibrations. The result reports how far each one moved, and its uncertainty then includes the calibration accuracy. Held exactly pins each camera where its calibration puts it, and the uncertainty covers the tracking alone.
Two or more calibrated frames, spread across the clip, make the answer far less dependent on any one calibration, and let the calibrations check each other. A second calibration at a different camera position also fixes the scale of the camera's travel, with or without tracks on the road surface.
road surface
A feature on the road surface lies where its ray from the calibrated camera meets the road, so its position is known from the calibration frame alone. Those features are what give the camera's travel its scale. Features anywhere else are solved in three dimensions from the way their direction changes as the camera moves.
tracked features
Paste the Video section of a Virtual CRASH report, headings and all. Each track is one scene feature followed through the frames in which it is visible. Tracks may start and end at any time as features enter and leave the frame.
Name a track "ground 1", "ground 2" and so on when the feature is on the road surface, and "point 1", "point 2" and so on for anything else, such as the top of a pole or the corner of a building. Capitalization does not matter, and "road" works in place of "ground". Tracks left with their default names, or given other names, follow the setting under road surface.
Track features that stay still: pavement markings, cracks and joints, curb corners, sign posts, building corners. Nothing that moves, and nothing reflected, such as a highlight on a window. Spread them across the frame rather than in one group, and keep six or more visible in every frame, with several carried from one frame to the next as others come and go. When the camera moved, at least three of them should be on the road surface, visible in the calibration frame.
results
The camera path is copied as one row per solved frame: t, x, y, z, yaw, pitch, roll, the order the animation controller takes. The CSV adds the 1 sigma of each value and the tracking residual of each frame.
| Track | Role | Frames | From (s) | To (s) | x | y | z | 1 sigma | Residual (px) | Note |
|---|
| t (s) | x | y | z | Yaw | Pitch | Roll | sigma xyz | sigma ypr | Tracks | Residual (px) |
|---|
Input as sent to the engine
method
The calibration frame fixes the camera's position, orientation and lens at one instant. In that frame every tracked feature lies on a known ray from the camera. A feature on the road surface lies where its ray meets the road, so its position in the scene follows at once. Any other feature is placed in three dimensions from the change in its direction as the camera moves.
The solution is grown outward from the calibration frame, forward and backward in time. Each new frame is solved against the features already placed, and places the features that first appear in it, so a track that begins late still contributes. Every camera pose and every feature position is then refined together, holding the calibration frame fixed, until the features project as closely as possible onto the pixels that were tracked. A robust weight keeps an occasional mistracked point from pulling the answer.
Turning is always determined by the tracks. How far the camera travelled is determined only up to an overall scale unless some features are known to lie on the road surface, which is why those features matter. With none, the camera is solved as turning about its calibrated position, and the result says whether the tracks agree with that.
Uncertainty is propagated from the fitted pixel residual through the full solution, including the correlation between frames. It does not include any error in the calibration itself, which every frame inherits.
Use of this tool is subject to the Virtual CRASH End User License Agreement.
Virtual CRASH Camera Tracker, interface 4.0.0
more in Virtual CRASH 6
This tool follows the camera. Virtual CRASH 6 calibrates it in the first place and puts the result to work in the scene alongside the survey data.
- Camera calibration and matching. Solve camera position, orientation, field of view and radial and tangential distortion from reference points, on or off the ground, taken from point clouds, orthomosaics, scanner data or Google Maps imagery.
- Projection into the scene. A calibrated camera projects its video or still back onto the terrain and any object set to receive projection, so footage and survey data can be compared directly.
- Point and object tracking. Manual point tracking, automatic point tracking and automatic object tracking, each producing speed against time.
- Track editing. Added in the Summer 2026 update. Tracks become editable polylines. Drag a control vertex in 3D and the pixel location is recomputed, or open the image plane to set the pixel and the frame time directly. Insert or delete points, merge tracks built by any method, and watch the speed graph update as you work.
- Dashcam workflows. Frame by frame camera tracking for position and speed from a moving camera, and point tracking against surveyed scene features.
- Export. Track point position against time appears in the dynamics report, which is the format this tool reads.
See Easy Video and Image Analysis for worked examples, and the Summer 2026 update for the track editing tools. Free trial.