Quick ‘n’ Dirty guide for making photogrammetric models with Agisoft Photoscan

Ok, this isn’t really necessary, but I’m posting it for completeness sake as part of an upcoming blog post.  This will just give you a quick rundown on how wiz through Agisoft’s Photoscan and generate a model.  If you’d like a more in-depth piece, I suggest Heinrich Mallison and Oliver Wing’s paper in Journal of Palaeontological Techniques, available here (PDF).

 

Step 1a. Import photos

You can either do this the laborious way;

Workflow->Add Photos

Or you can just drag and drop photos into the workspace .

Step 2. Align Photos

Click Workflow->Align Photos

Then select the relevant options.  Let’s go for ‘high’

Step 3. Build Dense Cloud

Go to Workflow->Build Dense Cloud.

I’d recommend not going for ‘Ultra’ – it will crash most non-specialist machines, and the result will be an extremely dense point cloud that isn’t necessarily any more accuracy.

Step 4.

Workflow -> Build Mesh, and select the appropriate options.

You can view the mesh by selecting any of the pyramidal buttons at the top:

Step 5.

To texture the model, go to ‘Workflow -> Build Texture.’  I generally go for a texture size of 4096 x 1, but you can select whatever is appropriate.

View the textured model by selecting the right most pyramid at the top.

Step 1b:

Of course, any nerd worth their salt will try to minimize button presses and computer baby-sitting, and to that end Photoscan allows you to batch process the whole thing.  To do this, go to Workflow-> Batch Process, and then hit add, change ‘job type’ to align photos, change the settings accordingly.  After hitting ‘OK’, click ‘Add’ once more, and change job type to ‘Build Dense Cloud’.  Carry on creating a new job for each of the steps above, then when it’s done, hit ok.  If you’re worried about crashes, make sure you tick ‘save project after each step’.

Note that you can add multiple sets of photos to your workspace and set the batch to process them all, allowing you to generate multiple models with one batch – e.g. overnight.