This will be just a short post to give an update on my progress with photogrammetry since I last blogged about a few weeks back. I’m still using the wonderful 123D Catch cloud application that has been developed by Autodesk, and it continues to produce great results. I’ve updated the workflow somewhat to allow for the exporting of a 3D PDF final product and that’s what I’m going to talk about now.
Currently the process goes as follows:
1. Take a series of photos of an object with your camera.
a. The photos should be taken in conditions of low contrast (a cloudy day with no artificial lighting works best).
b. The subject and its environment should not include shiny surfaces.
c. If possible, it is often worthwhile creating a narrow field of view in which all areas of the central object are in focus and the background is left slightly blurred.
d. A total of about 20 photos is needed for a small mobile object while anything up to 50 shots may be needed for larger subjects such as a building.
2. Process the photos using 123D Catch. A tutorial can be found here.
3. When the model has been generated and downloaded, open it in 123D Catch and export it as an OBJ.
4. Download the trial version of SimLab Composer 3DPDF Edition and the SimLab Plugin for 3ds Max. These will allow you to export 3D PDF files from 3ds Max. The trial allows you to export thirty 3D PDFs.
5. Import the 123D Catch OBJ into an empty scene in 3ds Max.
6. Now click on the <SimLab> menu and select <PDF Export>. You can choose from a number of output settings here.
7. You now have a high quality 3D PDF of your photographed subject!
Click here to download a 3D PDF that I made of Psi figurine that I shot yesterday. Note that you may be asked by the PDF plugin of your browser whether you wish to trust this document. Select under the <Options> button to trust this host one time only. Click on the white background of the PDF to activate the 3D plugin. I’ve just noticed that the built-in PDF browser plugins in Mac OS X do not seem to display the 3D content. I was however able to right-click on the link, download the file and open it in Acrobat 9.0 successfully.
While there are a few problems with the model, I’m pretty happy with the overall result and considering the whole process only takes about 10 minutes to complete, I think that it’s a viable alternative to the 3D scanner as long as you are not looking for super-accurate end models. The other major benefit of photogrammetry is its ability to take much larger subjects. My next challenge will be to do the same with a large-scale subject such as a building.
It seems that smartphone PDF viewers or iPads don’t display the 3D content.
Does anyone know of a way of viewing 3D PDFs on an iPad?
(Frank Lynam, 21/04/2012 11:34:32)