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Messages - pbourke

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General / Re: size of the 3d model
« on: April 17, 2019, 06:47:50 AM »
My approaches
1. Use scale rules and therefore create a scale model in MetaShape. See attached.
2. Export as is, scale in external  software to a known/measured dimension.
3. Export as is, scale to unit cube bounding box and apply real scale in viewing software.
I use meshlab for 2 and 3.

General / Comment/bug about forum attachements
« on: April 17, 2019, 06:44:53 AM »
I mentioned this before but it hasn't been fixed.
When replying to a forum question if I attach an image that is too large I get the error "attachment greater than 768kb". If I scale the image to under 768 and repeat, I then get the error "attachment greatre than 512".
Rather annoying and time waster when one is only trying to assist others in the forums.

General / Re: How to delete part of the dense model
« on: April 17, 2019, 06:31:37 AM »
Standard way to delete dense point cloud is using the tools as shown in the attached.
Common pipeline is to clean dense cloud before meshing.

General / Lens question
« on: April 17, 2019, 06:12:29 AM »
I have a large number of small objects to be reconstructed.
I've done a few using the Canon 100mm but that is a 1:1 lens and only works well for objects down to 2cm long, on a full frame sensor.
I would like to know whether 1:2 or 1:5 lenses can be used. For example the Laowa 60mm or Canon EP-E 65mm, see
This is where my knowledge of optics and relation to MetaShape are deficient. They are both a single focal length, but can zoom from infinity to close range, and I believe the image size changes significantly during focus.
Anyone understand this stuff?

A couple of comments

- I wouldn't worry about the GPU, my understanding is it won't make any difference from a model quality perspective, only the time taken.

- With regard to the quality of the results, what are you trying to reconstruct? There are well known/understood problem cases. For example smooth featureless surfaces, highly specular or reflective surfaces.

- And lastly and more speculative .... I've had mixed success with mobile phones. One of the issues I imagine is that phones these days are doing all sorts of processing on the images, often without you knowing or being able to do anything about it. I wonder if this processing which can include global changes can degrade coherence of what would otherwise be good across image feature points. Even with my DLSR capture I turn image processing/enhancements (or whatever the particular manufacturer calls it) off.

General / Masks
« on: March 14, 2019, 05:42:23 AM »
Can I have some suggestions on when one chooses to apply masks to keypoints or tiepoints?

General / Re: Can I edit Texture?
« on: March 14, 2019, 04:16:55 AM »
I always do it external (manually) to MetaShape, of course sometimes the texture is easier to edit than other times.

Feature Requests / Save chunk views
« on: March 14, 2019, 04:00:55 AM »
It would be most helpful for the last view of a chunk were saved with the chunk.
A time waster at the moment when I switch between chunks and the camera view of the chunk I'm switching from is used instead of the camera view from the last time I viewed the new chunk. I need to continually realign/reposition the camera ... switching between chunks is a fairly common exercise during manual marker placement.

This is an old question, but I'm interested in the answer also.
My feeling is no, the focus does not change the derived parameters. It would be kind of pointless if it did because typically one is going to focus differently for each shot of the actual subject anyway.
Certainly I focus on the chess board when doing a lens calibration.

General / Re: Problem with camera positions
« on: March 13, 2019, 11:49:56 AM »
I can confirm, after doing a careful, 15 shot camera calibration the issues seemed to have disappeared. As an example see
This "nut" is less than 1cm across. While the mesh detail isn't obvious from this, it is extremely good.
So I'm keen to understand why, using the 100mm Canon Macro .... does it mean the internal model for narrow macros isn't a match to reality?
Will repeat the calibration next with the same lens but another 100mm of extension tubes.

General / Re: Problem with camera positions
« on: March 12, 2019, 03:42:10 PM »
Thanks for the reply.
Actually, I did a quick lens calibration and it seemed to fix things.
Will do a better calibration tomorrow and see what happens.

General / Problem with camera positions
« on: March 12, 2019, 09:32:55 AM »
I'm a fairly regular used of MetashapePro.
Today I used a 100mm Canon Macro lens on Canon5D MKIII to capture a small nut.
On a tripod, in good light and high aperture, 75% of surfaces closest to the camera is in good focus.
I used a motorised platter, 20 degree steps around 360 degrees and 4 heights.
I created masks, but actually it didn't make any difference to the problem.
What I get can be seen in the attachment showing the sparse point loud and camera positions, part of the capture wedge camera positions are rotated around to overlap with another section of the 360 camera array.
Is a perfect 20 degree capture some sort of pathological case?

Face and Body Scanning / Re: Photogrammetry Array for Sale
« on: March 12, 2019, 07:55:18 AM »
Please send full specs (
Particularly interested in the rigging and camera automation.

General / Extension tubes on lens
« on: March 06, 2019, 02:54:32 PM »
I've just reconstructed some small beads using a Canon5D MKIII and 100mm prime macro lens.
However, to maximise the size of the objects on the sensor I would like to use some extension tubes. A quick test seems to suggest this will take me from using about 1/5 of the sensor to over 1/2.
I can't test on the actual objects as they are in storage at the museum, but I wondered if there were any issues I might encounter? For example, the EXIF data won't reflect the presence of the extension tubes.

General / Re: Camera positions?
« on: March 06, 2019, 02:44:29 PM »
Thanks ... sloppy thinking on my part.

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