Creating 3D model from phone photos - best settings

[Kerrowman]

Sainjin said that the one of the online resolution settings was capped at High and could not be set at Ultra. Maybe that’s a problem but min_num_features does appear to be critical in my case as indicated in this text from the manual:

I will tinker around with that more. My stone is obviously too ‘bland’ and similar from some angles, especially when close up.

Good of you to offer me to use the file but I have to find a way around this as I have lots of ‘objects’ to model.

I think the solution will be to adjust settings more or, if necessary, reshoot all the pics leaving no gaps and try again with my regular settings that can be done with my RAM. Still lots has been learnt

[Saijin_Naib]

The difference between high and ultra can be significant, even if you’re cranking up --min-num-features. At a certain point, you’re going to be missing valid tiepoints due to the image resizing for feature extraction that happens below Ultra.

Disabling prematching (–matcher-neighbors 0) or setting it really high can sometimes compensate. Same goes for using HAHOG features sometimes.

[Kerrowman]

There are lots of variables to play with but I can’t see HAHOG mentioned in the user guide (Lightening Options).

[GaryStebbins]

I have run into the problem of Sketchfab’s 100MB limit. I was able to get around it in some instances by converting all of the PNG files to JPG files and editing the .mtl file point to these JPG files before uploading. The JPG files are substantially smaller than the .PNG files, and I did not notice any reduced quality in the 3D model displayed in Sketchfab afterwards.

[Gordon]

I notice you had resize to :2048 in the Lightning settings, can that be set to No resizing?

One thing I did notice in the pair matching for the stone was the extremely high number of fails, where >20 matching features could not be found.

[Saijin_Naib]

Check this back-of-the-napkin summary I just wrote here until I write up something more formal and substantial for us all

Feature-Type Explanations

I need to write this up formally, haha. Thanks for the reminder! Real quick back-of-the-napkin: SIFT = Safest bet, performant and robust AKAZE = Can sometimes deal with lower-resolution images better HAHOG = Incredibly slow, can sometimes match more robust than SIFT ORB = Can be significantly faster than others, limited to 15k features currently, can handle noisy data So basically, throw SIFT at everything. If it doesn’t work, maybe try HAHOG if you’ve got the time. After that, come ask us…

[Kerrowman]

I didn’t see the option not to resize images for upload so I assumed it takes them full res because Lightening has the capacity?

I will have another look when I return from trip

[Kerrowman]

I look forward to your fuller descriptions of these terms in an updated ‘Lightening Options’ guide. At the mo they don’t mean much to me

[Kerrowman]

That would indeed make a difference but all my images are converted from HEIC to jpg automatically when exported from Apple Photos to the folder where I keep them for specific projects.

Another big factor on final size is the High - Ultra settings, amongst others.

[Gordon]

@Kerrowman

That would indeed make a difference but all my images are converted from HEIC to jpg automatically

I think Gary is referring to the texture files used in the 3D model, which are saved as .png format.
Files that look like this:

[Kerrowman]

Ah ok. So there’s an option to have them output to the textures folder as Jpgs instead of pngs.

[Gordon]

I think you have to manually convert them. I don’t remember seeing that option, although I haven’t actually looked.

[Kerrowman]

Fair enough. I can do a whole folder in a few clicks with an Apple ‘Quick Action’

[xLagonDragonx]

I’ve been using this site for viewing 3D models instead of sketchfab simply for the memory cap. It’s been working pretty well. I only use it to view the model.

Online 3D Viewer

[Kerrowman]

Thanks. I’ll give it a whirl. I found the excellent P3D.in by hunting around.

[xLagonDragonx]

I hadn’t seen that one before, looks awesome.

[Kerrowman]

The ‘auto-rotate’ feature is nice and not available in Sketchfab

[GaryStebbins]

Yes, I manually converted them. Having an option to output the texture files as JPEGs would be desirable.

[Kerrowman]

Can one edit the .mtl file in a regular text editor and what should the revised line look like - just a file path change?

[Gordon]

Yes, just replace all the .png with .jpg

It looks like this in Notepad in Windows.

newmtl material0000
Ka 1.000000 1.000000 1.000000
Kd 1.000000 1.000000 1.000000
Ks 0.000000 0.000000 0.000000
Tr 0.000000
illum 1
Ns 1.000000
map_Kd odm_textured_model_geo_material0000_map_Kd.png
newmtl material0001
Ka 1.000000 1.000000 1.000000
Kd 1.000000 1.000000 1.000000
Ks 0.000000 0.000000 0.000000
Tr 0.000000
illum 1
Ns 1.000000
map_Kd odm_textured_model_geo_material0001_map_Kd.png
newmtl material0002
Ka 1.000000 1.000000 1.000000
Kd 1.000000 1.000000 1.000000
Ks 0.000000 0.000000 0.000000
Tr 0.000000
illum 1
Ns 1.000000
map_Kd odm_textured_model_geo_material0002_map_Kd.png
newmtl material0003
Ka 1.000000 1.000000 1.000000
Kd 1.000000 1.000000 1.000000
Ks 0.000000 0.000000 0.000000
Tr 0.000000
illum 1
Ns 1.000000
map_Kd odm_textured_model_geo_material0003_map_Kd.png