visual sfm using a turn table

[Carl Fairbairn]

has anyone used visual sfm and a turn table ?

im having issue even walking around the image to even get a quality mesh

[Dave PSB]

If the camera is fixed and you are rotating the object, then I don't think that will work. The program uses fixed features in the background to key off of. Keeping the object fixed and rotating the camera around it on some sort of jig is an option, but obviously cumbersome.

[Benjamin Ducke]

Hi. This can be done and is merely an issue of photographic technique. Essentially, (Visual)SfM must be tricked into 'thinking' that you have moved in a circle around the object. The challenge is that your photos must not contain any structure in the background. Since VisualSfM (actually: any SfM software) assumes that you (or rather: the camera) are moving around the object, it will get completely confused if it detects (opposing) movement vectors in both the background and the object on the turntable. I had success with a white cloth that I used to cover the desk on which I had the turntable. I chose a cloth and desk big enough so that I could take pictures without picking up any discernible background features in the camera's viewfinder. When rotating the object, make sure that you don't get very large angular differences between the shots. It should take about 40 shots for a 360° model. You also need to make sure that your depth of field matches the depth of the object. This probably means that you will need a strong lighting setup, so that you can work with a small aperture.

On Fri, Jul 28, 2017 at 5:28 PM, Carl Fairbairn <carlfai...@gmail.com> wrote:

has anyone used visual sfm and a turn table ?

im having issue even walking around the image to even get a quality mesh

--
You received this message because you are subscribed to the Google Groups "VisualSFM" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vsfm+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Samaneh Rabienia Haratbar]

Hello, 

This is Samaneh, a PhD student at university of Missouri Columbia. I just found your email in the internet. Actually I am working with visual SFM and I have the same problem as you. I was wondering if you could find a way for using turntable and visual SFM? 

Regards,

Sam