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Author Topic: Setting up a Photogrammetry Rig  (Read 30098 times)

Exhale

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Setting up a Photogrammetry Rig
« on: November 14, 2013, 02:20:05 PM »
Hi guys,
I've been fallowing this forum for a long time and I managed to register finally.
There was a problem with confirmation e-mail with "yahoo" mail. Had to get another e-mail address sth like gmail or from other email service provider. For admin's information. :)

So,I have read lot's of informations about your experiences. I do appreciate to you all about those wonderful topics. Thank you guys.

I would like to ask for your advice;
I can say, Canon 600D is one of the best camera to have it in the ring, as it provides sharp photos.
What do you think about Canon EOS 600D + 18-55mm Lens ?   Is it good for a begining?

I was planing to get 10-15 Canon 600D cameras.
How many cameras would you recommend for 360?

What is the best for snapping? DSLR Remote Pro Multi-Camera Breeze systems looks good for Canon 600D.

Thanks in advance,



fabberlounge

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Re: Setting up a Photogrammetry Rig
« Reply #1 on: November 15, 2013, 09:24:57 PM »
Hi,

We are working with a 48camera setup ( mainly Canon 600D, some 1100D), they are all equipped with the standard 18-55mm objective. As far as my experiences goes, it works fine. Of course a 40(or 50mm) fixed lense objectiv deliveres improved quality, but esp. for a setup with limited space its nice to adjust the focal length. Agisoft is a great tool, even a mixture of different focal length within one setup works fine. ( even though it is not recommended). We are using Smartshooter for multicameracontrol, easy to use software for a good price ( in comp. to Breezesys). Out of my experience, for a 360 full body rig, you need at least 40 cameras, and that is challenging... the more the better, or you think of a turntable solution, depending on how dynamic your scans should be....
We are producing photosculptures, for some example check out www.fabberlounge.com
good luck, all the best Andreas
Yes, we scan !

meshmixup

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Re: Setting up a Photogrammetry Rig
« Reply #2 on: November 16, 2013, 01:23:40 PM »
Hi Andreas,

May I know what is the focal length recommended for 360 scan? Thanks

fabberlounge

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Re: Setting up a Photogrammetry Rig
« Reply #3 on: November 16, 2013, 07:47:06 PM »
Hi,

we get really good results with 35mm, but have also tried to stretch it down to 24mm.. That is really the limit (distorsion), in general I would say the closer to 50mm the better. We have only limited space (3.5m circle) so thats the main reason for us to use 35mm.

all the best Andreas
Yes, we scan !

Exhale

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Re: Setting up a Photogrammetry Rig
« Reply #4 on: November 17, 2013, 03:06:18 AM »
Hi,

We are working with a 48camera setup

Hi Andreas,
Thx for your help.  I want to ask, how long does your post processing(alignment, creating mesh..etc) take for 48 photos?

And after this post-processing, do you make edit?  how long does your zbrush take?
I am just trying to understand the process for 48 camera setup.

Thx

fabberlounge

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Re: Setting up a Photogrammetry Rig
« Reply #5 on: November 17, 2013, 08:06:56 AM »
In average at medium quality about 1 hour, depending on your hardware. We are using the scans mainly  for 3D prints, so we dont need a high res file. We take about 20-30 shoots of each costumer (optimized file organization is a must), align all photos and choose about 5 chunks for batch processing. The postprocessing in ZBrush and Photoshop takes another 1-2 hours, but that varys a lot. ( depending on the complexity of the pose, outfit, scan quality, and my personal mood  :) ) The more scans I do the better it gets, its a lot of trial and error... I have calculated about 20minutes for the photoshooting, 20 minutes active work of choosing the optimal data, overnight automated batch processing (about 2-3 costumers) and max. 2h postprocessing.
That is just the way we do it now, I am sure we will improve our workflow, get more cameras will definetely help. Another tip, we are already using the newest beta version of PS....

Good luck with your setup, bye Andreas
Yes, we scan !

Exhale

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Re: Setting up a Photogrammetry Rig
« Reply #6 on: November 18, 2013, 12:09:15 PM »
Thanks for sharing your experiance with us.  ;)

didexe

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Re: Setting up a Photogrammetry Rig
« Reply #7 on: November 19, 2013, 07:48:49 PM »
Hi Andreas, we are using a rig of 48 1100 Canons with  18-55 kit lens set at 18 which works quite well having in mind our space is just 2m diameter. The quality of results depends mainly of the type of clothing that people wear but sometimes we have wierd resiults that I would like to discuss with someone with similar set up. Can you please share some experience with clothing colours and textures. We have big percentage of missing legs even with good clothing sometimes. I can upload some images later.

Daniel

fabberlounge

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Re: Setting up a Photogrammetry Rig
« Reply #8 on: November 19, 2013, 10:54:00 PM »
Hello Daniel,

Yes the clothing has a big influence, I get best results with all sorts of denim and leather, also the naked skin works really good. A nightmare are shiny and "flat" surfaces, also little kids skin (face) has sometimes weird difficulties... Also not good are big patterns, smaller ones are sometimes ok. I always make a shoot with my calibration dummy first in order to export and import the cameras. That calibration is really helpful, also a shoot without the model for using masks from background is a nice option. Its funny what you say about legs, this is where I have less problems, the tricky bit are hands in some poses... But that is really depending on camera positions... and light. As Lee Perry told me, its a hell lot of trial and error involved(I am sure you have experienced the same). May I ask you where you from? are you already in business or planning to launch sometime? looking forward to see your images, will also post some work I have done lately...
all the best Andreas
Yes, we scan !

meshmixup

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Re: Setting up a Photogrammetry Rig
« Reply #9 on: November 20, 2013, 12:00:03 PM »
Hi Daniel,  I guess your legs problem is due to lacking of overlapping photos. I noticed the lowest camera from each camera pole (says 10 poles) is not enough to calculate the point cloud of legs. Try to downtilt some cameras. ;)  Lighting could be another concern. It is quite impress that 18mm can work in a 2m circle. But I think it is not easy to capture motion.

Hi Andreas, For your case of using 35mm, do you have difficulties in capturing varies poses? I want to capture a pose of swinging tennis racquet in a 4m circle using 35mm 550d. Do you have any advice? Do you think 24mm can do a better job? :)


Cheers
Jim
« Last Edit: November 20, 2013, 12:07:08 PM by meshmixup »

fabberlounge

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Re: Setting up a Photogrammetry Rig
« Reply #10 on: November 20, 2013, 07:06:16 PM »
Hi,

The problem with wide angle settings are some distorsion effects, esp. for texture mapping (mosaic), the mesh itself works ok even with 24mm, so its just a challenge of available space and correct position of cameras. I would recommend f-stop F11 or even bigger ( if your light/ lighting is good enough for ISO 100), to have a bigger DOF.... Not sure if you can cover a 4m circle completely, but maybe that is not necessary if you synch. movement with shooting...I did some scans of people jumping, sometimes it works good, but esp. with hand position and covered details .. its always a trial and error... so multishot is the answer...

good luck, Andreas
Yes, we scan !

meshmixup

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Re: Setting up a Photogrammetry Rig
« Reply #11 on: November 21, 2013, 01:40:49 PM »
Hi,

Yes, keeping a clear images is the key and getting many object details in each photo as possible. It is a trad-off in object details if I need to cover larger volume..... :-[ Also I found lighting is quite challenging to get every part "well" illuminated :P 

I saw you are fixing cameras in pair, is there any advantage?

Cheers,
Jim

Exhale

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Re: Setting up a Photogrammetry Rig
« Reply #12 on: November 21, 2013, 03:33:30 PM »
Allright then,
So what would you say guys about  50mm fixed lens instead of 18-55mm lens?  Can you tell me prons ands cons please.

thx

fabberlounge

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Re: Setting up a Photogrammetry Rig
« Reply #13 on: November 21, 2013, 11:47:33 PM »
Hi Jim,

In my experience, with stereo pairs the aligning and mesh quality gets better, at the moment my rig i a bit chaotic, a mixture of stereo pairs, landscape and portrait, 50mm, 35mm and 24mm, Canon 600d and Canon1100d... the amazing fact is that its just working fine THANK YOU AGISOFT !!! its always some sort of magic I dont have (luckily) to understand...

Exhale,
I am only working with the 18mm-55mm lenses, for my purpose its good enough, again I have only limited space so flexibility is a must for me. Definetely a fixed lense equipment delivers better quality, so if you have enough space (and cameras)  I would go for that...

regards Andreas
Yes, we scan !

meshmixup

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Re: Setting up a Photogrammetry Rig
« Reply #14 on: November 22, 2013, 05:36:11 AM »
Hi Andreas, it is quite impress that ps can well handle with different focal length in one shot. Do you do lens calibration? It seems there is no significant difference for using the same focal length.... ::)

One more question, is there any setting in ps required for stereo pairs? ........Pair Preselection? ;D

Hi exhale,
Prime lens produces sharper images, I think it's good for portrait. Canon may have plan to produce cheaper pancake size prime lens other than existing 40mm which is a good option :)