Known cameral positions

[Karlsc]

OK so I'm confused.. I created a fixed rig. and it still took me a while to get it to give me a good rendering. But the most recent run had me start with 23 cameras on the rig of which Zephyr light " recognized" 14"

So I pulled out those 14 images into a separate directory and re-ran Zephyr lite with exactly the same settings.. and this time it only recognized 5 of those 14 cameras.

And the Export Calibration exports a file of some sort, but it can't seem to be imported.

what am I doing wrong?

[Karlsc]

ignore the previous one

[Karlsc]

[Karlsc]

The rig is fixed to the boat itself. - I've been simulating it by putting the cameras on stands at fixed distances from the boat in an attempt to find the optimal configuration that will have all cameras included in the synthesis. if we take one side of the boat I'm currently looking at

1 camera on the bow looking aft

2 cameras on the stern (one each side offset by about 1m in my test and about 4 m in the full sized boat) looking forwards

1 camera midships offset from hull looking forwards diagonally

1 camera midships offset from hull looking aft diagonally

1 camera 3-4 meters above looking down.

each is a 4k 30fps "Sports" camera. I can add more cameras "within reason" since these are cheap. hence

I've been adding in the older "360 view" cameras in an attempt to find out if I need more cameras for synthesis.

The goal is to start with generating a 3D model statically and then use these cameras to capture dynamic frame by frame additions to create a Voxel based movie

so I have also tried using a 4k moving scan of the boat to create the baseline model. and then have the additional cameras added in. and use those as deltas against the baseline.

currently my testing model is a Laser so Front to Aft cameras are separated by about 4 meters

Side cameras are offset from centerline by about 2 meters See attached image layout

[Andrea Alessi]

Do you have a fixed rig? If so, simply reconstruct something by placing something easy to reconstruct, so you can save the parameters.

Once you have saved them use the load photos with known parameters (of your second scan) in pro or aerial. This will skip entirely the SfM phase and use the parameters of the previous project.

This is different than using constraints for cameras.

[Karlsc]

Yes, you can save parameters of a successful reconstruction and use them for later reconstruction in a fixed rig scenario

right, but that doesn't help the initial fixed rig create a successful reconstruction
Is there a way to do that?

[Andrea Alessi]

Yes, you can save parameters of a successful reconstruction and use them for later reconstruction in a fixed rig scenario

[Karlsc]

If your cameras are fixed, take a good dataset and export the camera internals and externals. You'll need Pro or Aerial in order to load photos from known parameters.

I'll be happy to help if you can send me the original data you are working with.

What do you mean by a "good dataset"? one where it has successfully constructed a model? Does that mean for the cameras individually? or in their fixed positions?

[Karlsc]

>>

and you need to calibrate the setup once first

<<

how is that done in an open fixed location? I know how to calibrate a single camera but that doesn't help when they are separated by at least 5 meters.
the camera layout I have is set up so that any point has at least 4 cameras on it

there is no single original video. there are 8 separate videos each fairly heavy since it took some time to set up the cameras initially. I've given up pulling frames using the built in tool you guys have. It doesn't work very well: for example on a source I know to be 30fps I can only set to pull 25 FPS..

so I've moved to using FFMPEG and pulling a frame per frame. I know this means that the I-frames are being calculated and synthesized but when I inspect by hand I damned if I can tell which frame is a b-frame and which an I-frame

[Andrea Alessi]

If your cameras are fixed, take a good dataset and export the camera internals and externals. You'll need Pro or Aerial in order to load photos from known parameters.

I'll be happy to help if you can send me the original data you are working with.

[Karlsc]

>>

and you need to calibrate the setup once first

<<

how is that done in an open fixed location? I know how to calibrate a single camera but that doesn't help when they are separated by at least 5 meters.
the camera layout I have is set up so that any point has at least 4 cameras on it

there is no single original video. there are 8 separate videos each fairly heavy since it took some time to set up the cameras initially. I've given up pulling frames using the built in tool you guys have. It doesn't work very well: for example on a source I know to be 30fps I can only set to pull 25 FPS..

so I've moved to using FFMPEG and pulling a frame per frame. I know this means that the I-frames are being calculated and synthesized but when I inspect by hand I damned if I can tell which frame is a b-frame and which an I-frame

[Andrea Alessi]

the general rule is that you need to see the same point you want to be reconstructed from at least 3 images, taken with a different position and rotation. Obviously, the better the images the better the result.

using different type of cameras is not going to help when there are very few images. If the camera position is know (and you need to calibrate the setup once first) you can use the XMP setup (pro/aerial only), however, if the number of camera is super-low, the subsequent results are still not going to be excellent, unfortunately.

Can you share the original input video ? I may be able to help you more if i have the original input.

[Karlsc]

Alternatively, if the camera positions are known and fixed - that would help the math in identifying overlaps non?

[Karlsc]

using these same cameras in video mode with auto iextraction, I've had the software autoidentify as few as 5 images and construct at least something from that

which is why my question is about the minimum number of cameras needed