inaccurate volume

[syuan]

Hi all,

I was working on a project that reconstruct a 3D model of a box. I used about 200 photos which were taken by iphone. I used ruler to measure the model's width, length and height. But they are always two-fold over the real size. Does anybody know why it is inaccurate, and how to optimize it? Any suggestion would be appreciate.

Thanks.

[Alexey Pasumansky]

Hello syuan,

Have you used markers or scale bars in PhotoScan project in order to reference or scale the model during the processing?

[syuan]

Hi Alexey,

Thanks for your reply. I haven't tried markers or scale bars yet. Could I add markers to the model generated by Agisoft, and input the reference value to estimate the volume?

[stihl]

If you have not scaled your project with either markers (GCPS) or a sale bar then your model will have *no* value other than looking pretty.

Photoscan has no idea what the size of the box is unless it's scaled. Otherwise it can be a box the size of ..a box, or a box the size of a house.