Wrong camera positions when shooting with static camera

[maxze123]

Hi!
I just got into this stuff and found this software. But I have one problem:

I shot an object while moving around it with my camera. When I brought it to Photoscan it worked great. Then I tried the same object with a static camera and just turning the object. But with those pictures it doesn't work at all. It seems that Photoscan just places all the cameras at the same position. Is there a tutorial on how to shoot with a static camera or what settings do i have to use?

Thanks for helping

Greetings,
Max

[Alexey Pasumansky]

Hello Max,

When tunrtable scenario is used, you need to mask our the static background, otherwise it will cause false matching points to be found on the static parts of the scene.

Also I can suggest to check the following video-tutorial on the related topic (it also describes the principles of the automatic background masking):
https://www.youtube.com/watch?v=9_F-b2hxP_o

[maxze123]

Thanks for the quick response!

Yeah I watched that videos a couple times already..

I mapped out the background, too. So it's strange that it's not working. But I'll test it with another object and see whats the result

[Alexey Pasumansky]

Hello Max,

Probably you are not using Mask File Names field in the Import Masks dialog properly. If you have single camera position, then you need to use only one background file and the mask filename template will be a static filename.

[maxze123]

Good evening! Today i received my turntable so I tried shooting with a static camera again.

So I set everything up. The first shot is the background image for masking:
http://www.directupload.net/file/d/3937/xln3c4ku_jpg.htm

Then I shot 46 pictures turning the table. Here's one example shot:
http://www.directupload.net/file/d/3937/f6womrkr_jpg.htm

Then I got into PhotoScan and Added the photos. Then I went to Tools -> Import -> Import Masks. There I selected Mehtod: From Background. Then I wrote the name "IMG_9485_mask.jpg" and applied it to "All cameras". The masks were pretty good. So I went to align photos at the highest quality. And after 10 minutes or so this is the result:
http://www.directupload.net/file/d/3937/ygeyb8u8_jpg.htm

PhotoScan just places all the cameras at the same position and it kind of messes it up. What do I have to do?

Edit: I should add that yesterday I got pretty good results while putting the Eifel Tower on my tripod and moving around it with the camera. Here's yesterdays result:

http://www.directupload.net/file/d/3937/7d7wuk6a_jpg.htm

[Alexey Pasumansky]

Hello Max,

Can you post a screenshot of the Photos pane thumbnails switched to the Show Masks mode?

[maxze123]

Sure:

http://www.directupload.net/file/d/3937/zvj3xhin_jpg.htm

Seems like it didn't work badly but also not that good. Maybe I should cover the turntable with some cloth?

[Alexey Pasumansky]

More or less it was fine. You can vary tolerance value for better results, I assume.

And have you checked on "Constrain features by mask" option in the Align Photos dialog?

[maxze123]

And have you checked on "Constrain features by mask" option in the Align Photos dialog?

Nope thats not checked. Should I check it?

Edit: I checked it and thats the result of the dense point cloud:

http://www.directupload.net/file/d/3937/xhmj3uea_jpg.htm

It got better but still it places the cameras not 360° around the object.

[Alexey Pasumansky]

I think that better masking should help.

Also you don't need to build dense cloud, if you see that the alignment is not good.

[maxze123]

So I did some good masking by hand. Bust still it messes up the angle somehow. Cameras get positioned about 90° around the object so it misses data at the other 270°.

This is the result:

http://www.directupload.net/file/d/3938/f9zrcskx_jpg.htm

Maybe I try another object. Something more simple like a rock

Greetings

[James]

Perhaps the 4 sides of the tower look too similar.

You could try again with a sheet of newspaper under the tower, and leave the newspaper unmasked so that photoscan has a bit more information in each frame to work with.

Since it is a flat plane under your tower you can always trim it out of the dense cloud easily before meshing stage.

[maxze123]

Perhaps the 4 sides of the tower look too similar.

Yeah it seems that was the problem! I tried another object and it worked really great.