Agisoft Metashape

Agisoft Metashape => General => Topic started by: haonguyen91 on September 08, 2017, 11:04:12 AM

Title: Dimension Agsoft
Post by: haonguyen91 on September 08, 2017, 11:04:12 AM
Hello All ;
I have some question about dimention agisoft.
I have buil 3D model on Agisoft , however 3Dmodel is not correct when i use Ruler.
And when i export file to Geomagic control X and check dimension. Result is not correct.
Please let me know and guide me : How to work about it
See attachment.
Thanks :-* :-* :-* :-*
Title: Re: Dimension Agsoft
Post by: Alexey Pasumansky on September 08, 2017, 03:52:47 PM
Hello haonguyen91,

What kind of referencing information you are using to apply the scale to the reconstructed model?
Title: Re: Dimension Agsoft
Post by: haonguyen91 on September 09, 2017, 04:01:49 AM
Hello Alexey Pasumansky ;
I have flying Cam and smartphone for got picture.
Thanks
Title: Re: Dimension Agsoft
Post by: haonguyen91 on September 09, 2017, 07:35:49 AM
Hello all;
Who can help me ? i am readly need it . :'( :'( :'(
Thanks
Title: Re: Dimension Agsoft
Post by: Dave Martin on September 10, 2017, 10:03:42 PM
haonguyen91,

You need to tell PhotoScan something about your real-world otherwise it can only work in abstract co-ordinates. The same pair of images could be of an object 10 cm away with the cameras 5cm apart - or objects 100m away and cameras 50m apart. The only way you can get measurements out of any photogrammetry system is by putting reference information in - that might be something like a couple of measurements between points if it is a small object, or a set of survey ground control points if it is an aerial survey; or, if you have sufficiently accurate camera positions, you may be able to infer scale from them.

No reference information => no real-world dimensions.

DM
Title: Re: Dimension Agsoft
Post by: haonguyen91 on September 11, 2017, 04:59:47 AM
Hello Martin ;
Thank alot for you reply. I am uderstanding your answer. But How to putting reference information in Photoscan ?
With marker ? Ruler ?...if ok. Can you send me some video guide it ?
Email : haocadcam91@gmail.com
Thanks
Title: Re: Dimension Agsoft
Post by: SAV on September 11, 2017, 10:26:47 AM
Hi haonguyen91,

Point clouds and associated datasets such as meshes, DEMs and orthomosaic generated using PhotoScan are dimensionless (= cannot used for real world measurements) unless you include 'reference information' such as camera locations (= geotagged images), ground control points/markers, scale bars or a combination of these.
Note that the accuracy of the model will depend on the accuracy of the 'reference data'. For example, if the location of your geotagged images is only accurate to a few meters, you cannot expect to achieve measurements with centimeter accuracy from computed datasets.

You might find the PhotoScan tutorials quite useful. They show you how to use ground control points.
http://www.agisoft.com/support/tutorials/beginner-level/

All the best.

Regards,
SAV
Title: Re: Dimension Agsoft
Post by: haonguyen91 on September 11, 2017, 11:56:14 AM
Hi SAV :
Thank for your reply.  i have a question. How to creat CSV ? I dont know anything about it. Thanks
Title: Re: Dimension Agsoft
Post by: rossnixon on September 11, 2017, 01:29:38 PM
https://www.computerhope.com/issues/ch001356.htm
Title: Re: Dimension Agsoft
Post by: haonguyen91 on September 14, 2017, 05:02:49 AM
Hello All ;
i cannot creat CSV because i dont understand about it.When I follow your instructions, there are two main problems:
1 .How to putting reference information in Photoscan ?
2. How to creat CVS .
and have problem( Please check attachment )
Please help me
Title: Re: Dimension Agsoft
Post by: SAV on September 14, 2017, 05:27:51 AM
Hi haonguyen91,

I suggest to have a look at some of the official PhotoScan tutorials first:

1. http://www.agisoft.com/support/tutorials/beginner-level/

2. http://www.agisoft.com/support/tutorials/intermediate-level/

They should help you to solve your issues.

All the best.

Regards,
SAV
Title: Re: Dimension Agsoft
Post by: haonguyen91 on September 14, 2017, 06:02:22 AM
Hello SAV ;
I tried to follow instructions .but I got the problem right from the first step. it is import CVS.I can not display the parameters of the photos.
Title: Re: Dimension Agsoft
Post by: SAV on September 14, 2017, 07:00:53 AM
Hi hoanguyen91,

The workflow is described in the PhotoScan manual on page 44.
Download the PDF from here: http://www.agisoft.com/pdf/photoscan-pro_1_3_en.pdf

I've added two TXT files that you can use as a 'template'. One for importing markers/ground control points and the other one for camera locations. This is how your CSV (or TXT) files should look like. They both use TAB as delimiter.

Note that the camera location ID needs to match the name of the image you have imported.

I hope that helps.

Regards,
SAV