Adventures on Planet Xerox

INTRO This post is a step by step guide to 3d scanning with an MS Kinect using KinectToSTL and Meshlab. Since this model was created a few months ago ReconstructMe and Matherix 3dify have changed the playing field somewhat, allowing for 360 degree 3d scans in one go. I have not been able to get either of these apps to work / provide workable meshes at this time, thus my demo outlines the method i used to achieve this model using multiple scans, aligned in Meshlab and a small amount of work in Rhino. Fig. 1. Example of finished product printed on a Makerbot TOOLS apps KinectToSTL Meshlab Rhino hardware MS Kinect for Xbox 360 Makerbot / 3d printer tripod, zip ties / rubber bands swivel chair subject to scan SOFTWARE Download and install KinectTOSTL, Meshlab and demo version of Rhino. CAPTURE 3D DATA, part 1 A. Attached MS Kinect to tripod securing with rubber bands or zip ties. I used a couple of small bits of sheet rock to create a cylindrical hole to marry the base of the Kinect to the tripod shoe, and in turn snapped that into the tripod. Fig. 3 MS Kinect Place swivel chair a few feet away from the Kinect as shown in fig 3. Fig 3. Kinect set up on tripod with subject seated on swivel chair. B. Connect the Kinect to your computer via USB. Boot up KinectToSTL. Adjust the width, height and distance of the scanning plane to best capture the features of your subject, as shown in Fig. 4. When you are happy with the scanning area, making sure to capture as much of the face, shoulders and top of head as possible click the “export to STL” field.  Test this step. Each time you want to capture a 3d scan you need to press this “export to STL” field.  To find your exported .stl files goto Apllications>KinectToSTL>data Fig. 4 KinectToSTL interface. CAPTURE 3D DATA, part 2. The subject to be scanned should try to maintain as still a posture / composure as possible. As them to either shuffle their feet to rotate - or rotate them yourself manually. The more rotations you perform the better your overall scan. For the model shown in Fig. 1 we did 12 rotations / 12 individual .stl files. See Fig. 5. Fig. 5 Rotating subject 360 degrees. CLEANING YOUR MESHES You’ll probably need to clean up your scans prior to alignment. This is part of the grunt work of this process. ReconstructMe and Matherix 3dify do this step for you. : ( Boot up Meshlab. IMPORT each mesh, so FILE> IMPORT> goto Applications> KinectToSTL>Data and open up each .stl file individually, teh intention of removing the background noise and exporting the inidividual mesh file as an .obj or .stl Fig. 6 Scan of face in Meshlab prior to cleaning. Meshlab has several really important tutorials on Youtube. Prior to cleaning your meshes you really should watch all of these tutorials, as they explain the Meshlab interface and tools much better than i can or will here. a.     Meshlab Basics: Navigation http://www.youtube.com/watch?v=Sl0vJfmj5LQ&list=UU70CKZQPj_ZAJ0Osrm6TyTg&index=13&feature=plcp b.     Meshlab Selection: Part 1 http://www.youtube.com/watch?v=xj3MN7K6kpA&list=UU70CKZQPj_ZAJ0Osrm6TyTg&index=11&feature=plcp Meshlab Selection: Part 2 http://www.youtube.com/watch?v=Bc3GdJ6Ddsc&list=UU70CKZQPj_ZAJ0Osrm6TyTg&index=10&feature=plcp c.     Meshlab: Alignment (joining meshes together) http://www.youtube.com/watch?v=4g9Hap4rX0k&list=UU70CKZQPj_ZAJ0Osrm6TyTg&index=16&feature=plcp For further info on Meshlab check out: Meshlab YouTube channel http://www.youtube.com/user/MrPMeshLabTutorials/featured ok…. now u should be a certified Meshlab Ninja! the next step is to take this new skill set and apply it to your scans, clean away all of the unwanted background scan / noise. pay attention to your selections and make sure you haven’t selected parts you want to keep when u hit delete….. you should go from something like this…. Fig. 7 Fresh scan with “projected noise” to something like this…. Fig. 8 Cleaned up scan minus “noise” EXPORT each individual scan as a separate .obj file and save to a new folder, to keep everything nice and tidy. ALIGNING YOUR MESHES Fig. 9 Aligning your meshes in Meshlab Instructables has this neat step by step guide, on aligning your meshes using Meshlab that i used to make this happen: http://www.instructables.com/id/Using-Meshlab-to-Clean-and-Assemble-Laser-Scan-Dat/ Import all your meshes into a new Meshlab project. SAVE it (not export) as a Meshlab Project (MLP). Meshlab is a crashtastic program save early and often. You should get something like this… Fig. 10 Spooky, huh? Our next step is to Align the Meshes. Go back and check out the Instructables demo, in fact keep it open in a separate browser window. You can only align one layer at a time. I would “hide” the layers you are not aligning. ALIGN TOOL Fig. 11 Aligning Meshes in Meshlab Click on the yellow “A” button to activate the Align tool in Meshlab. 1. Click the button “Glue Here Mesh” to select the Mesh you wish to attach to. 2. Click the button “Points Based Gluing” to activate the pop up. FIG 12. Use the gumball to get the scans in the same position, so u are viewing them from the same angle. Fig. 13 Align tool Zoom in a close as u can. accuracy is everything here. Double click on areas of the scan you wish to marry together. Essentially you are telling the program that these two points in space are the same. And in this fashion you will create a 360 degree model from several scans. Select at least 8 points ideally. Move the scans around to select points from different angles. When scanning a head look for anatomical features such as the bridge of the nose, ears, dimples, eyes - features that stand out. 3. After you hit “ok” go ahead and click “Process” in the other window to finish this stage. Repeat as needed. till you get something like this…. Fig 14. All meshes aligned FLATTEN YOUR LAYERS this is where Meshlab crashes. but persevere, there seems to be no special reason it does crash so keep trying and it’ll work eventually, most likely. probably. Fig 15 Flatten Visible Layers Fig 16 Apply Poisson Mesh filter The next step is to create a watertight mesh from your aligned meshes that will be good to print with. To do this you need to apply the “Poisson Filter” to the flattened layer. Goto> Filter > Remeshing… >Surface Reconstruction: Poisson. Fig 17. Setting the Octree Depth + Solver Depth Set your Octree Depth to 10 and your Solver Divide to 9 (according to Youtube) and assuming ML don’t crash —- bingo! Fig 20. Printable 3-d mesh. EXPORT ASAP AS STL. don’t wait for ML to crash. we’ve worked too long and hard for this moment. ; ) …. next adding a base in Rhino….