How to clean up model created from photogrammetry (holes)?

Support Basics & Interface
#1

Hello,

I’m using photogrammetry to make 3D models of some of my artwork. The problem I’m running into is that when there are holes through the object, the created mesh is bridging the holes. I’m new to Blender.

What I have tried:

  • I have imported an SVG of the 2D hole shape and tried a boolean operation, but it’s difficult to line up the shapes correctly.

Is there a particular tool or workflow that would help me?

The real world object:

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Blender model, red lines indicate where the holes are closed.

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blender model:
http://rideauworks.ca/shared/trinity.blend
with textures (large file)
http://rideauworks.ca/shared/trinity.pack.blend

Thanks
Greg

#2

Hi @Greg9504,

If you want more precise 3d model for that specific rock, I suggest taking more photos for your photogrammetry process and you might get much better result. Also you can try to reconstruct it at higher poly counts, you can then decimate/reduce it as you need.

Your 2D shape is not suitable for boolean operations (It needs to be “water tight”, so no holes etc.). I remeshed your shape using some auto remeshing tools in Sculpting mode. It then works fine. You’ll probably need to edit/fine-tune that shape. Here is the edited file: trinity_edited.zip (3.5 MB)

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2 Likes
#3

Thanks so much for taking a look. I forgot I even included the 2D shape. Yes I was having a problem getting it to be “closed”. Other SVG files that I tried didn’t have the same problem when I extruded them. With your fix I was able to do the boolean after adjusting the angle that the two objects intersect and got the holes cut, well at least close enough.

I then went back to my original file and tried to reproduced what you did to get the 2D ‘open’ extrusion to close. I tried the remesh tool but I’m not able to get it to work like you did. Could you tell me the rough steps you did?

This is after applying the remesh with the settings shown, for Voxel Size I used the same value that was shown when I opened that panel in the file you edited. I did try other sizes, but none had satisfactory results.
Thanks again.
Greg.

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#4

Sorry, I wasn’t clear enough for that step, I did some manuel clearing before using the remeshing tools.
Here is what I did roughly:

  1. First I removed double vertices (Mesh>CleanUp>Merge by Distance).
  2. Then I deleted some inner faces (Mostly around red circles).
  3. Also I dissolved some stray vertices (ctrl+x) (Mostly around orange crosses).
  4. Then I run the remeshing tool in Sculpting mode (Shift+R to preview voxel size, Ctrl+R to execute it).
    image
    image1046×446 69.7 KB

If you this cleaning on 2D shape before extrusion, it might be better/faster.

1 Like
#5

Thanks again.