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Author Topic: Creating line drawings of models - which software to use?  (Read 6454 times)

ThomasVD

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Creating line drawings of models - which software to use?
« on: August 30, 2014, 01:08:42 PM »
Hi everyone!

I'm looking for a good workflow where I can export models from Agisoft PhotoScan, and then trace relevant features (in the geometry, but preferably also on the texture) in order to output a lines drawing containing only the relevant details.
The actual case study will be a shipwreck site, where I want to trace both a top view and cross sections of the wreck for archaeological purposes.

Available software (which I think might be useful): 
- Rhinoceros 4.0
- Illustrator
- Quantum GIS

For the top view I suppose I could just export an orthophoto of the entire site and trace that in Illustrator (unless someone has better suggestions?) but for the cross sections I was thinking of some approach where I imported the model in Rhino, dissected the model to the cross-section I wanted to draw, and then traced that. However Rhino doesn't appear to be very good at "reading" or showing the texture generated by PhotoScan (ie the texture is always a lot less good in Rhino), which is an issue.

I would be very grateful to hear from anyone who has had some experience with similar issues!

Thanks in advance,

Thomas
« Last Edit: August 30, 2014, 01:40:14 PM by ThomasVD »

gheflorian

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Re: Creating line drawings of models - which software to use?
« Reply #1 on: September 01, 2014, 01:14:45 PM »
In the office we have Innovmetric Polyworks that is very good at drawing vectors over 3D models and then it can be exported as 3D polylines.

ThomasVD

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Re: Creating line drawings of models - which software to use?
« Reply #2 on: September 01, 2014, 06:37:53 PM »
Thanks a lot for the reply but I'd rather figure this out either with freeware or with Rhino (since that's what most people in our discipline seem to be using)!

David Cockey

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Re: Creating line drawings of models - which software to use?
« Reply #3 on: September 01, 2014, 07:36:25 PM »
I use Rhino to create lines drawings of boats based on PhotoScan models. I export the models from PhotoScan to Rhino as textured OBJ models (model names must not have spaces) and usually use "Render" mode for viewing the chunks in Rhino. I've been using version 5 of Rhino for quite a while but version 4 was satisfactory.

ThomasVD

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Re: Creating line drawings of models - which software to use?
« Reply #4 on: September 04, 2014, 01:03:51 PM »
Thanks David, I'll give that another try! Although last time I worked with PhotoScan imports in Rhino I remember being frustrated about the way Rhino was handling the texture - but perhaps I didn't use OBJ file that time, I'll give it a go!

David Cockey

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Re: Creating line drawings of models - which software to use?
« Reply #5 on: September 04, 2014, 04:08:09 PM »
Rather than "draw" directly on the imported mesh, I usually create a grid of curves using the Contour command in Rhino and then create the curves I want by snapping to the grid curves.

For Rhino questions try the Rhino forum at www.Rhino3d.com > support > Forum or directly at
http://discourse.mcneel.com/

Limpopo_River

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Re: Creating line drawings of models - which software to use?
« Reply #6 on: September 05, 2014, 11:50:03 PM »
This discussion on a similar topic might be of interest:
http://forums.culturalheritageimaging.org/index.php?/topic/301-contouring-rti-data/

Also, a team at Princeton is collaborating with Cultural Heritage Imaging,  http://culturalheritageimaging.org/Technologies/Algorithmic_Rendering/, a California 501(c)3 non-profit, to develop the Collaborative Algorithmic Rendering Engine (C.A.R.E) (still in development) to allow one to generate line drawings from Reflectance Transformation Imaging (RTI), which renders normal maps of objects' texture. 

David Cockey

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Re: Creating line drawings of models - which software to use?
« Reply #7 on: September 13, 2014, 02:10:27 PM »
Thanks David, I'll give that another try! Although last time I worked with PhotoScan imports in Rhino I remember being frustrated about the way Rhino was handling the texture - but perhaps I didn't use OBJ file that time, I'll give it a go!

"Render" viewing mode in Rhino uses directional lighting by default which sometimes can cause portions of a textured object to have dark areas in shadows. I have needed sometimes to adjust th lighting and add additional lights to fill in shadows.