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Messages - aphextwin

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1
General / Object Scale
« on: June 02, 2015, 12:47:58 PM »
Hi there,

we are scanning objects for 3d printing purposes. I detect markers in my scan (which works fine) and add a scale bar, edit the length of the scale bar and then click on update. After that I export FBX for further editing in zbrush.

With this workflow it never gives me the right real-world-scale of the object, its always about 0,06 m.

What am I missing?

Greetings!

2
General / Re: Agisoft PhotoScan 1.1.0 pre-release
« on: October 16, 2014, 06:00:18 PM »
Hi there,

on my two osx-machines I was not able to start a server or client-node by using the commands stated in the tutorial file. Is network-nodes not yet implemented for osx?

Thanks!

3
General / Re: photoscan zbrush texture issue
« on: August 08, 2014, 09:35:13 PM »
nobody knows?  :'(

4
General / photoscan zbrush texture issue
« on: August 08, 2014, 10:47:38 AM »
hi,

when I do 3D-Scanning with Photoscan I like to clean up my models in zbrush afterwards. For my convenience I rotate and move my model to be exactly perpendicular to the floor so it is easier for me to handle. After doing the cleanup I often put a box below it as a replacement for the raft for my fdm-printer so it looks nice. As you can imagine I work in PM3D and Dynamesh  knowing that I loose UV-coordinates. That has never been a problem as the FDM-printer does not support colored printing.
Now my issue is that I have to work for a z-printer where I need my textures. I know that workaround with retexturing in photoscan by creating uv-coordinates in zbrush and using them in photoscan (keep uv). The problem with that is that I loose the orientation when I move my object in zbrush so I cannot  retexture it in photoscan. Probably I have to change my workflow but can somebody give me a help with that?

thanks!

5
General / Re: Question - How to Place Model at Point of Origin?
« on: August 04, 2014, 12:33:56 AM »
I'm interested in this question, too.
I use zbrush to repair my meshes. One of the disadvantages is that I'm not able to center the object in zbrush because when I do this and re-import the mesh into pscan to rebuild textures, the mesh is not at it's origin anymore and turns black after the texturing-process. But working with zbrush without moving/scaling the mesh can be quite a pain. What about that?

6
General / Color Correction
« on: December 31, 2013, 01:29:02 PM »
Hi there,

I've got a simple question:

What exactly (!) does this "color correction" do?

Thanks!

7
General / Re: Agisoft PhotoScan 1.0.0 pre-release
« on: November 08, 2013, 04:04:51 PM »
The 64-bit windows download link to the 1.0 pre-release seems to be broken...

8
General / Re: UAV - GOPRO workflow
« on: September 19, 2013, 11:15:38 AM »
As I mentioned in another post:

Go with the Ricoh GR Digital IV as it quite a large sensor, fixed zoom lens with an acceptable focal length and global shutter. It supports RAW-Images and several interval-modes out of the box. You can link it to your analog fpv-equipment. And it only costs about 430 EUR at amazon.
Imho the best Cam for small and mid-size UAV.
For large UAV there are of course better cams with fixed zoom lenses. There is always a better product ;)

9
General / Re: UAV - GOPRO workflow
« on: September 18, 2013, 09:07:24 PM »
First: The GoPro can't be used for Agisoft since it uses a rolling shutter.
Second: In order to work in low light conditions and still getting nice quick-shuttered videos, the GoPro increases the ISO to extreme values which introduces incredible noise.
Third: The GoPro has a fish-eye lens which can't be used for SfM.

And because I don't give much about theory, I tried it myself with the GoPro Hero 2 and my Octocopter, just for fun. last year.

And failed.

10
General / Re: Scan of small objects using Macro lens
« on: August 18, 2013, 10:32:11 AM »
Imho a camera-rig for macro-SfM is a waste of money as you're to set focus etc on every camera manually.  What is your aperture?

I'd recommend you to play around with aperture/shutter and let iso be the lowest as possible. Don?t forget to not take much higher apertures than about f/13. But anyways, with the Canon standard macro (60mm I guess, connected to a eos 600D) I got very nice results even at higher apertures. With my eos 5D Mark III I had dof-issues.

are you interested in samples of small items (about 1cm)? I could upload a sample animation.

I think that the noise that non-sharp images gives you is far beyond what higher apertures do to your results. But that's only my oppinion.

11
General / Re: TOP cam for low-altitude UAV
« on: August 07, 2013, 09:16:58 PM »
very nice,

do you have any other examples?
mich w?rde interessieren ob man die kameras auch synchronisieren kann, also 2 oder 3 gliechzeitig ausl?sen, wei?t du das?

gru?
jerry

Hi,
your question is:
Is it possible to synch multiple of these cameras?

The answer is: yes, but...

This camera is not hijacked like chdk. With chdk (and SPM) you're able to synch multi cameras at a very small period of time. This is not possible with the ricoh, BUT of course you can combine multi cable shutter releases for this camera and they will all shutter at the same time. But just not as synchronized as the CHDK/Canons do.

12
What makes me a little "dizzy" in this discussion is my fear that it's going nowhere ;-)

Try to figure out what major constraings you?ve got:

- shutter speed (should be fixed at the longest possible value)
- DoF

Determine how big EXACTLY your sharp room should be, which means in other words, how small/wide your f-value can be. this automatically constraints your ISO as it is the only value left you can trigger. Another point concerning shutter-speed is: Can you increase your light-level?

If this does not work, your only chance is to get a "quicker" sensor that reduces less noise at higher ISOs (i.e. without bayer-matrix (like Leica Monochrome... haha) and take texture-pictures extra) or get a smaller sensor to physically increase DOF. Imho the noise a smaller sensor introduces is much less than the noise that brings higher ISO / missing sharpness by larger f).

If the Nikons don't to the job, forget about them. A large sensor is not ALLWAYS a good choice as I mentioned some posts above. I did quite decent quality object-reconstructions with a turn-table using a Canon G11 one year ago.

13
Hi All for people interested to understand few things about cams, lenses and good quality of results  recommend to read carefully this two links..... 

1. http://www.dxomark.com/index.php/en/About/In-depth-measurements/Measurements/Sharpness

2. http://www.dxomark.com/index.php/en/Publications/DxOMark-Reviews/Looking-for-new-photo-gear-DxOMark-s-Perceptual-Megapixel-can-help-you

After you understand the stuff behind it, you can SAFELY choose proper lens for your cameras  8)

The Perceptual MPix measure confirms certain rules of thumb such as “a 12 MPix full-format camera is sharper than an 18 MPix APS,

and the prize is 'sharper', too ;) if you need i.e. 18 cameras for a multi camera rig this is a quite important point. btw aps sensors have less requirements for lenses as they don't use a smaller part of the lens. imho the eos 1100D with a 35mm fixed zoom lens does a good job concerning sharpness, vignetting etc and the costs. honestly, for SfM I wouldn't use zoom lenses at all. But small sensors are not a bad idea in every way as they deliver 'better' depth of field at smaller apertures so you can take a shorter shuttertime, so a good (!) compact camera (like ricoh with fixed zoom lens) can get into consideration too.
what I want to point out is that this topic is not binary (good camera/bad camera) ;)

Concerning the overall signal/noise ratio, full frame is clearly the best, but I guess this point is clear...

14
100% agree.. image-quality is very poor!

did you try the canon eos1100D with 35mm fixed lens?
This combo comes quite cheap and it can be synched with magic lantern, I guess.

15
General / Re: TOP cam for low-altitude UAV
« on: July 30, 2013, 12:38:15 PM »
Exposure / focus etc can and should be fixed. That's another reason why I use this camera. You don?t have to 'configure' some strange chdk-settings that do work (or sometimes not).

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