Has anyone tried out Autodesk Memento for 3D scanning?

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(Michael Scholtz) #1

Has anyone tried out Autodesk Memento for 3D scanning? kinda seems like 123D catch all grown up .

(Alexander Gryson) #2

Yep, @Alvise_Rizzo ​, one of our 3D designers, swears by it for his photogrammetry projects. Has gotten excellent results, even with the beta. (Though the scan won’t work occasionally, when it does it works excellently he says)

(Marcus Wolschon) #3

I have a rotation table with 3 colored objects (cube, pyramid and hexagon) attached to give a scanner something to track.
Would something like that work for photogrammetry of black, highly curved objects with few features to track?

(Whosawhatsis) #4

@Marcus_Wolschon stereophotogrammetry requires the computer to visually identify features to track them. This is highly dependent on shadows, so a black object would not work well, but a rotation table wouldn’t work at all. Unlike depth cameras and structured light scanners, stereophotogrammetry uses the existing ambient light (and the shadows it produces) along with the objects color to identify features. This means that the lighting of the object can’t change during the scanning process, and a rotation table would make the direction of the shadows change every time it moves, making it impossible for the software to identify features.

In theory, if you had a completely featureless background and all of the lighting in the room was attached to the rotation table, it might work, but for stereophotogrammetry, you’re really supposed to move the camera and NOT the object.

(Marcus Wolschon) #5

Okay. I didn’t know that details about the shadows.

(Alexander Gryson) #6

We’ve had success hanging the object from fishing line and moving around it.

(Marcus Wolschon) #7

@Alexander_Gryson did your objects have sharp edges that could be tracked?

(Alexander Gryson) #8

It’s been with multiple objects, but generally solid, hard edges ones. Sticks, bottles, things like that.

(Mark Fuller) #9

@Marcus_Wolschon ​ You could get contrast by application of tape dots or contrasting dust.
Are your black objects gloss or matte? If matte, you could project a pattern onto the surface with a projector(s) that remain stationary with respect to the object. If glossy, you could surround the object with well-lit patterns that move with the object and are reflected in the surface. Look up deflectometry for info on the technique. You can also move the pattern with the camera. Some systems use stripe patterns on a display panel. Seems to work well for automotive finish inspection. 
Contact me if you want links to papers and etc…

(Chris Purola (Chorca)) #10

So, in theory, you could use a rotation table, provided the camera is rotated on a ring around the outside of the object rather than the object itself being rotated? Perhaps a small pedestal in the center that stays still and a movable ring?

(Marcus Wolschon) #11

@Chris_Purola_Chorca That would require a LOT of space and having no background to distract the software would require even more space.

(Chris Purola (Chorca)) #12

Yes, it wouldn’t be very small, but maybe something like a white ‘object photography’ box with a single light shining into it to create shadows? I suppose it all depends on the size of the objects you want to scan…

(Marcus Wolschon) #13

I’ll stay with my Kinect V1+Skanect and wait for anyone to implement something for my Kinect V2 on MacOS/Linux.

(Windows emulator doesn’t work because VMware/VirtualBox/… doesn’t emulate DirectX10)