I am doing a very simple camera motion tracking, and I almost always get the errors: E1227 07:10:20.242158  6528 intersect.cc:159] POINT BEHIND CAMERA 1: 01.12694e+07 00000-502884 -2.22473e+07 E1227 07:10:20.244158  6528 intersect.cc:159] POINT BEHIND CAMERA 1: 01.12479e+07 -1.40083e+06 -1.93429e+07 E1227 07:10:20.246158  6528 intersect.cc:159] POINT BEHIND CAMERA 1: 016253.3 -19688.9 -87439.6 Unable to reconstruct position for track #2 'Track.002' Unable to reconstruct position for track #3 'Track.003' Unable to reconstruct position for track #4 'Track.004'  like this:  The video is simple; little movement and all the tracking points are visible from start to end. Only 8 points so far, I wanted to keep it simple to understand the errors above somehow. First frame:  Half way:  Last frame:  The blue/red lines all look good to me; none loose track, they keep on point. If I check the &quot;Tripod&quot; on the Solve tab, it works, but I get a huge error (Solve error: 11.62 px), which also is very odd to me. If I now change the &quot;Sensor width&quot; to 16.000 and &quot;Focal length&quot; to 17.00 (which is what I think that the Huawei P30 has), then the error just disappears, but I still get a solve error of 13.79.  Changing &quot;Sensor width&quot; and &quot;focal length&quot; resolves this error? But why? Im not even sure that the numbers I entered are correct.
373
Whenever I do camera tracking in Blender the reconstruction is always zooming out or not on the axis. I have a great quality camera, but the end results of the camera tracking always has the model sliding. If you have a solution please tell me.
35368
I render a short movie. I set the camera to the circle curve to make it fly in circle. The problem is after render, the camera is a little shaky. Can anyone help me? Thanks first.
120323
I am currently writing some code to do multilateration using TDOA and currently struggling and wondering if anyone has any reference code that can be used as a test case with some sample data that I have!  At the moment I am unsure if it is the code I have written or whether it is the geometry of the points that is off.  One example group of packets that I have received is  station1 = [50.919149572907784,-1.005043823556842,90.729]; station2 = [50.8304,-1.21956,0]; station3 = [51.0569,-1.26224,100];  stations = [station2,station1,station3]; timestamps = [28704.175275109, 28704.175334203, 28704.175334875];   My code currently locates this to 50.910447339754654,-1.2347406519401736 which I am 99% sure is wrong!  Does anyone have any code that can verify this at all?  One bit of code I am testing against and get very similar results is
181
I added tracks and stuff, but then when I tried to solve motion track, there was a error that said:     Some Data Failed to Reconstruct   and it also said to look into the console for details, which I did. This is what the console said:    By my understanding, my video is 372 frames long, and Blender is cutting the footage at 318 for some reason. Here is the image of the scene:    Why? Here are links to  and also . Also the next morning I did a camera solve, but then most of the frames went red.
46675
I'm trying to track body parts relative to a person's torso. I see quite a few questions about using MEMS accelerometers and gyros for dead reckoning, and they confirm my suspicions that various factors greatly limit their usefulness for these sorts of applications, but I'm seeking clarification of these limits:   What exactly are these limits?  Other answers have addressed why these limits exist. Naturally the specifications the parts in the system in question and what is considered "acceptable error" for the system will both change the exact limits, but is there a single order of magnitude in time, or distance that I can expect dead reckoning to work? I'm well aware that over long distances (a few yards or so) the error becomes too large for most practical purposes, but what about within a few feet?  What can I do to improve these limits?  I'm currently looking at using an accelerometer and a gyro. What other sensors can I add to the system to improve the error rate? I know over longer distances a GPS can be used, but I doubt any consumer electronics grade GPS has fine enough resolution to help in my case.  Additionally, a general consensus seems to the only way to improve these limits past the point of improved sensors is to provide a reference not subject to error. Some systems solve this using cameras and markers.  What kind of reference points can a portable/wearable device provide?   I've seen the usage of radio waves to measure long distances accurately, but I can't tell if such a system could be accurate on such small scale (in terms of distance measured) using "off-the-shelf" components.
63465
I've been trying to track a footage taken by my Samsung Galaxy Note 8.0 (GT-n5100) tablet. It has a good 5 mp camera and I tracked the footage well. But the problem arises at the time of solving the camera. The solve error is too high (more than 2). I don't know the width the tablet's camera sensor or the focal length or any other specifications. So my question is, has anybody been able to solve the camera on footage shot by a smartphone and if yes,  what camera and lense specs did you feed to the Blender?
29918
I'm drawing a scene where the camera freely moves about the universe.  The camera class keeps track of the view (or look at) point, the position of the camera, and the up vector.  These vectors/points are then passed into gluLookAt.    Pan and zoom are nearly trivial to implement.  However, I'm finding rotation about the look at point to be much more of an issue.  I want to write a function Camera.rotate that takes 2 angles, one that rotates up/down and one that rotates left/right along an imaginary sphere that is centered about the look at point.  Is there an easy way to do this?  I've (briefly) read about quaternions, but I wanted to see if there was an easier solution given the relatively simple construction of my scene.
120112
I am using a smartphone for capturing photos and I need to estimate the camera sensor size (mm*mm). I have the resolution (in pixels) and the focal length (in pixels). I can also measure the size of any stationary object and its distance w.r.t the lens. Basically, I don't have a pixel-to-mm metric for any of the above parameters that I can use. Is there any way I can calculate that to estimate sensor size?
123503
I have an issue when generating an image sequence from a video clip. Pictures 1,2,and 3 are three consecutive images from a video clip. Picture 4 is a close-up of the heel of one of them. The camera is on a tripod. As you can see there is no issue with the brick wall, but with any moving part there is. The camera is a Panasonic HDC-SD100. The clip is AVCHD 1920/1080. If I use VLC to extract the image sequence there is no issue. I use all the default settings except for the rendering resolution which I set to 100% and image compression to 0%. I have the issue with Blender 2.79b and 2.80. With this image issue it is impossible to do camera tracking. Any ideas what I need to do in order to solve this. Best regards.
112995
When dealing with camera motion, its very sensitive to any movement discontinuities. Is there a way to easily achieve natural looking motion when dealing with complicated motion paths and timings?  Follow path animation feels too robotic unless I adjust all the keyframe easings carefully and this has to be re-done everytime the animation changes (the automatic bezier type just doesn't work).
25065
In the camera setting in motion tracking, how do I tweak the K1, K2 and K3 value properly. I was told that these values are not necessary to tweak but I do want to adjust it, just for the sake of perfection.
46601
Why can't I snap the point I chose to the target point.  I tried for a long time to do this, but no use!  Could some help me? Thanks !
30340
I know there is a ton of questions and answers about this topic, but none answers my question sufficiently.  Let's say I have a viewport view that I want to render in Cycles. Pressing ALT CTRL Numpad 0 aligns the camera to this view, but it does not solve the whole problem. The thing is, I want PRECISELY this view on the render, preferably in one click, without manually moving the camera back-and-forth, changing sensor sizes etc. fiddling that will remove the unwanted border that appears and blocks the viewport partially. This whole activity wastes a lot of precious time especially if you do this 10 times a day.  What this dream action should do:   match the render resolution (proportions) to the resolution of the current view (can the resolution of current view be read by a Python script?) make the entire view the camera view, without any borders, passe-partout etc. by automatically maneuvering sensor sizes etc. whatever is necessary to make it exactly the same view, the same camera lens angle.   Is it possible to write such a script that would do it all in one click?
15727
I currently use a Track to Constraint to make the camera automatically point to an empty.   In an animation the camera is moved along a bezier curve (follow path).   How could I change the curve and track to constraint at a certain frame to focus on another aspects of the scene?
51389
Pressing Ctrl Alt NumPad 0 causes the camera to teleport over and align itself to the current view in the 3D viewport. However, it usually takes up only a small portion of the view, meaning that you have to move the camera back to fit the same view you had before. Is there a way to set the camera view to fill more of the 3D viewport when using this feature?
114178
Is it something like the sensor captures a circular image and then what we get is the cropped version?  Something like this:    Or did I get it completely wrong?
37081
I already solve my camera and created 3d scene successfully. Now i want to do 2d track the original clip and by using solving data, i want to extract that specific point into 3d coordinate (as empty object or plain axes). How can i do this ?  Thanks