Here are a few pointers for camera tracking (for more details follow the links in blue text):
1. Prepare your scene carefully before shooting to make tracking and reconstruction easier
Avoid sudden camera movements to prevent blurry footage and rolling shutter artifacts. Blurry, shaky or otherwise distorted video is very hard to track and will result in ...
All camera lenses in the real world create some kind of distortion. CG imagery does not have the imperfections of glass.
Setting the distortion values for the lens is crucial if you are trying to do accurate scene reconstruction and integration with 3D generated elements.
To determine the values for a particular lens you can shoot a picture of ...
Here's how the stabilzation's supposed to work in Blender:
The trackers included in the 2D Stabilzation tab get pinned down.
The image then gets repositioned to keep those tracked points in the same place, effectively countering whatever move you had made.
Blender has no way to discern which movement is intentional and which isn't...
A workaround for ...
Update for posterity: An archive of this answer can be found at https://bvisness.me/2017/04/25/blender-masking-layers.html.
Blender has a feature called Masking Layers, which nicely accomplish exactly what you're trying to do. Put your content cube on one layer and your masking plane on another, then set the Masking Layer for the plane's layer. I got my ...
With the new affine/perspective tracking you can get much better tracking by having a marker that has some features within it. Here's a brief hierarchy of how I think about what makes a good tracking marker:
Some kind of point you can track the position of. Vulnerable to being lost due to noise. Can't track scale or rotation very well.
The red and green lines on the graph show you the speed of the trackers at a given frame. Green is vertical movement, Red is horizontal. The red and green curves will always start at zero in the first frame of the scene, and will move away from zero as the tracking points change position on the following frames. Objects closer to camera will move faster than ...
For proper tracking you don't necessarily have to know the sensor dimensions or lens size. What matters is to determine the field of view or angle of coverage for your particular camera.
That value can then be applied to any combination of sensor size and lens sizes.
One way to get a good estimate of your camera's field of view it is to shoot video of an ...
To track areas that are blocked by obstacles or temporary going off-screen. Move the tracking marker before the area is hidden by pressing GG and dragging the marker to another tracking point, or offsetting the marker in Track properties panel in Marker section by changing X and Y offset position. You can then continue tracking the scene under the offset ...
Let's say you've successfully tracked an object in your scene:
Go to the Solve Tab and in the Geometry section and click on Link Empty To Track.
That will create an Empty that, if seen from the camera, moves within the frame like the tracked object.
At this point you might want to add your image as background for reference and make it visible for the ...
A mostly automatic way to do what you want is to use a Plane Track
The workflow is like this:
Load your video clip in the Movie Clip Editor
Create a tracker on your image by clicking while pressing Ctrl and pressing the tracking forward button (or CtrlT)
Track at least four points within your video corresponding with the area you want to paste your "...
Removing the markers is quite simple:
What you need:
Scale accurate model of the mini-figures head
A million dollars and contacts at ILM :P
What you need to do
Align your model of the mini figure to the tracked head exactly even the slightest error can be catastrophic.
Project the image back onto the model head, using the UV project modifier. Be sure ...
Successful reconstruction can only be achieved with accurate tracking
Your error average should be under 1.0 pixels, preferably 0.3.
Issues with your file: Your tracking is not good...
Your trackers are too large, and have few distinct features. Don't track the center of a featureless object, try to track the edges that have contrast.
(read this post on ...
Blender can't do this (easily), but it is possible to do this with OpenSource Photogrammetry software (PPT and MeshLab) outside of Blender, then import the resulting model, see:
Example, blog posts.
First try deleting the big sliding errors, where tracked seem to deviate a lot from others, just select the big spikes and delete.
Then find the best sample region for keyframes, I think perhaps 40-70 looks cleaner.
Finally I turned on "Refine" using Focal Length, K1. This will force Blender to estimate the lens type and field of view.
After all that I get a ...
You will probably need to do it with dynamic paint, as Charles recommended, and it is possible without solving a camera motion:
You can easily set it up by tracking the wall where he is painting with a simple 4 point track, so you get 5 markers. Then, link empties to those markers, hook a plane's vertices to the wall markers and parent a cube or other ...
All available markers are used when creating a camera tracking solution. Markers that have moved off screen can be cleared of bad tracking data to help improve the solution.
By going to the last good frame and selecting the marker you can use Clean After or go to the first good frame and press Clear Before, you remove the tracking data that is contributing ...
Track the element over which you want to overlay the image.
With the tracker selected got to the Solve tab and in the Geometry dropdown, click on Link Empty to Track.
That will create an empty that is parented to the camera and moves with the movement of the tracked element.
Add the picture of you want to overlay one using Import Images as Planes
Blender is failing to reconstruct because it cannot get enough good tracking information to reconstruct the 3D motion for a section of the video, so it reconstructs only a portion of the shot. The frames where it failed are marked in red.
There are many reasons why your shot fails to track properly making the 3D reconstruction impossible.
I'll address a ...
As cegaton mentioned your current solution does not represent 3d space, because you don't have enough trackers. You can try the following workflow:
First enable object tracking
Try to track the head with 8-14 markers
Increase the search area of the markers, if the footage is jumpy
Solve your object track with a value bellow 0.6
Apply a camera solver ...
The mask control points can be controlled by trackers.
So track the hand (or the edges where the hand moves over the book cover) and parent those trackers to the mask.
To do that select the mask's control point, then shift-select the tracker to control it and press CtrlP. Now the control points will follow the tracker automatically.
Playing with track Weight may allow quick solving convergence, while keeping some (all) poor quality tracks.
Solve as usual, then run this script into a python console, and then solve again. Desired error is the wanted residual solve error.
Nearly magic, for use with many tracks detected automatically.
See github repository for an addon version.
Blam has been updated a bit since those tutorials.
Use the MCE (Movie Clip Editor) or Stabilizer, to load the clip. The Blam addon should appear in the Tools panel in a tab called Miscellaneous. Turn on the Grease Pencil in the Properties panel and add 2 layers. Set the color if you want to tell them apart.
To draw a straight line with GP press Ctrl + D ...
The issue might be caused by inconsistent decoding of your particular video codec by Blender, resulting in variation in the frame sequence you move through on the timeline. My suggestion would be that you convert the video to a discrete image format, like a PNG or JPEG sequence. A typical way to convert video to an image sequence:
ffmpeg -i "MyVideo.mov" -...
Blender currently uses a KLT-Tracker (Kanade–Lucas–Tomasi) which is documented here .
While algorithms like SIFT and SURF are patented, ORB (Oriented Brief) could be an alternative (BSD licensed) it was developed in 2011 and is already implemented in openCV
I have no idea whether there are plans to use other algorithms in Blender.
By default, motion tracking is set up to solve camera motion.
To enable object solving mode you need to click on the plus sign of the Objects Tab on the right side of the screen (if it's not visible press N)
and select Object.
Now Solve Object Motion is enabled.
When doing motion tracking you can set the origin of the scene on the Solve Tab's Orientation. Select a marker you want and press on Set Origin.
When you setup the tracking scene that particular tracker will be placed at the origin of your 3D scene. (to make the trackers into empties press on Link Empty to Track)
Those empties will be visible if you enable ...
Empties are added to the scene as a result of the perspective information obtained during tracking. So no, you cannot use the empties from one solution to track a different camera.
Watch "Track, Match, Blend" to learn how tracking data is gleaned from following features.
You probably want to use the "Track To" constraint. Then you can configure which axis should point to the object, and which axis should point upward. For a camera this would be typically -Z for the "To" axis, and Y for the "Up" axis:
In order to create the floor you have to solve the clip first. bundles are basically solve data for the track. Your error is probably caused by unsolved/incorrectly solved tracks.
From the wiki:
Bundles makes sense after solving the movie clip, and it works in the following way: the solved position of each track gets projected
back to the movie clip ...