I was always very skeptical about these kind of programs where you take a bunch of photos, press the button and “magic” happens. Well, I had to try this PhotoScan software by Agisoft, and see for myself. I was very impressed with the results and excited with the possibilities. It’s really easy to use, gives you great results and I have only scratched the surface of it.
Taking the photos
As rule of thumb, if you shooting environments don’t shoot from the center, instead go around near the limits of the set “looking in”. If you’re going for a prop photoscan shoot around it in a circular way, if possible rows from different heights so you can get near all the possible views.
In this example I took around 40 photos, you can experiment and see how much is enough to give you a nice point cloud to build the mesh.
PhotoScan is really easy to use, the first step of course is to add the photos using the main menu go to workflow > Add Photos. You can “help” the program providing masked images where you isolate the subject (removing sky, trees, etc) using photoshop or nuke and importing those in the menu Tools > Import > Import Masks. I just used the jpg’s from the camera in this case.
Now that you have your images ready, go to Workflow > Align Photos, the default settings are fine, you may want to reduce the accuracy if it’s taking too long to compute. Now PhotoScan will go through the photos and create a point could of your scene.
And here is where the “magic” happens, you will be impressed with the accuracy and speed of the software. Even without “meshing” the result, this data would be really useful. Now we just need to clean it before going through the mesh creation and texture extraction. To navigate around the scene use LMB to thumble , RMB to pan and Shift + left click to zoom in and out (dolly).
Cleaning the Point Cloud
Near to the selection tools you should find an icon Resize Region, that will let you crop the point cloud to the desired location and remove any extra floating objects around. Just drag the points around until you have isolated the object/set.
Now that we have cleaned the starting point cloud, the next step is to build a dense cloud. Go to Workflow > Build Dense Cloud. I have used the Medium quality preset, as you go up in the quality it will get slower to compute, Ultra high could take “forever” to compute. So start with medium and see what results you get.
After the process finishes, you will not be able to see the results without checking the Dense Cloud icon in the top bar that you can see the image above. Now you can really see the beauty of this software, rich and accurate detail with almost no effort.
Use the selection tools, lasso tool for example, to delete the undesired parts of the pointcloud, also click on the cameras toogle icon to hide cameras so you don’t accidentally delete them.
Now it’s time to build the mesh from the point cloud, going to Workflow > Build Mesh, the default settings will do fine, maybe you want to reduce polygon count, in this example I used the High preset.
Here you can see the resulting mesh, use the icons in the top bar no switch between viewport render modes.
So far we only have very rough textures, but we can get high quality maps for our mesh by going through the next Workflow step, Workflow > Build texture. Leave the default settings and set your texture size, here I choose 4k.
And here you can see the final result which is in my opinion very impressive with so little effort.
Export model and texture
The final step is to export the mesh and the textures if you want to, using the File > export Model. Now you can import the model into maya/zbrush and start the retopology fun
Try it yourself and see how this can help you, a good example that I remember was Bertrandt Benoit on the Bits of bread project, but he used 123D Catch from Autodesk.