Alignment of finished scan

[nyersa]

Hi there, new to the forum. Apologies if this has been asked before, but I couldn't find anything on preliminary searching. I am creating scans of objects using a David sls-2, and wanting to align the finished fused scan in 3d coordinate space. Right now I am opening up the finished scans in meshlab and doing the alignment there using the manipulators tool, but I would like to be able to do this in the David software. Is this possible?

[micr0]

RTFM http://wiki.david-3d.com/david3_user_manual/shape_fusion

µ

[nyersa]

The alignment of individual scans into a single finished model is not the problem, the problem is aligning the finished fused scan in 3d space. I could be missing it, but I don't see where this is detailed in the manual...

[MagWeb]

Pressing "C" on your keyboard shows the origin and the XYZ axes. You can manually move the reloaded fusion result.

Another thing you might try: Construct a "ground plane" oriented in X and Z in some third party application. Make sure that it is subdivided to be a dense mesh and its scale is of a size fitting to the object. Import this as well.
If your fusion result owns a flat surface (e.g. the ground plane of a statue) you can use DAVID's FreeAlign (maybe using ContactPair).

Meshmixer (free) also ships with a Align tool to orient a surface on a "zero" plane.

[nyersa]

Interesting! Ok so I got the origin and the axes displayed however whenever I try to rotate the scan the coordinate space moves along with it. Is there a way to lock the axes down so just the scan is moving without the axes so I can manually orient it?

[JDM Dyno]

made ground plane in VIA CAD and saved as obj then add to David then add your scan

note that blue line (z axis) is in up direction on the plane, green on the scan, I hold the ctrl key to move the scan to this position

Before

then do fusion

After
now I have blue line (z axis ) in direction I want it

I think the first scan is always the orientation of the fusion results so the ground plain needs to be first in the list, maybe if you can change the order of your scans in the list you would not need to use a ground plane not tried that yet but may give it a try if I get some time, been building a new rolling road so not done much scanning lately.

[JDM Dyno]

the Rolling road in case your interested

taken some time to get the rollers back from the machine shop!

[micr0]

the Rolling road in case your interested

dyno.jpg

rolling road.jpg

taken some time to get the rollers back from the machine shop!

Nice! Where is the eddy current brake? (P.S. I have a dynojet 250i

Sorry now back to the original thread.

I think Holding the control key was what the original poster was looking for. Holding the control key while right clicking and moving the mouse moves the model in space relative to the coordinate system as opposed to right clicking whit out the control key which just rotates the view.

µ

[JDM Dyno]

@ micr0 I have Land and Sea water brake setup on old home made 12 inch rollers, been mapping cars on it for 12 years, overdue new one now, still using the water brake for now on the new one as it works like a charm for me, new rollers are 20 inch

and back to scans: you need some reference plain or you don't know how much to move it, the origin marks move with the scan,
just tested and you can just move it and do fusion and the origin moves, so you can use a plane for reference then delete it and do the fusion of all the scans, the ctrl key is a very handy tool

[nyersa]

I knew about the ctrl-key option but was missing that you have to have something else in the scan to align it to instead of just in coordinate space. So, just to summarize, toss in something as a ground plane that is already properly aligned in coordinate space, then align your scanned object to the ground plane, then delete the ground plane. Seems a little cludgey to me instead of just being able to directly align a single scan in 3d space, but hey whatever it works for me!

[Vito]

I have found that the easiest program to place an object in the xyz coordinates is meshmixer, free simplified version of cad