Learn How to Get Great 3D Scans With Open Photogrammetry in 5 Easy Steps

Out of 51 entries, Capture 3D was awarded winner of the GE Aviation open innovation High Accuracy, High Throughput Inspection Technologies challenge. Capture 3D used its ATOS Triple Scan III non-contact blue light 3D scanner, capable of measuring up to 8 million points per scan, to complete the challenge. Participants entering the challenge had to demonstrate the ability to automatically inspect the blade portion of an off-the-shelf Victorinox paring knife in three minutes or less with accuracy of 10 microns and repeatability of 5 microns.

Capture 3D offers a complimentary Education Starter Package for teachers and professors to help educate our future engineers. Each package contains a PowerPoint lecture on the principles of photogrammetry and structured light technology, 30 USB sticks with free GOM Inspect software, ATOS for Education brochures and a classroom poster. Additionally, Capture 3D can provide onsite classroom seminars on the Free GOM Inspect software.

Get Great 3D Scans With Open Photogrammetry

Download

Patrick Letourneau (00:20): Hi, I'm Patrick Letourneau 3d artists, photogrammetry, NIST, and secret crime fighter. You've probably heard the term photogrammetry before, but maybe you thought it was a bit too advanced or complicated to try yourself. Well, I'm here to show you the technique for capturing incredible 3d scans of the world around you. Using tools you probably already have at your fingertips. Photogrammetry is the science of making measurements from photographs. Using multiple input images. Software is able to infer super accurate three-dimensional models that you can put to use better yet. You don't need expensive equipment or complicated software to get started. Just your cell phone and some supplies from around the house. In this tutorial, you'll learn how to set up objects for capture and adjust them into software, how to clean up and simplify your model texturing and baking normal maps. How to export the model into cinema 4d and Redshift, and the difference in quality between a cell phone scan and a commercial scanning setup. Before we begin, don't forget to grab the project files in the description below so you can follow along. Let's get started.

Patrick Letourneau (02:15): Obviously don't need to really explain that. You can see, uh, my movements here, I'm attempting to be systematic and kind of create a dome of pictures around this thing. Um, you know, you'll do a ring above the thing, and then you do a ring at the same level as this, uh, as your subject. And then maybe you can go do some orbits of special areas that haven't been covered previously here. You can see them shooting underneath the soul, probably not going to focus on the bottom of the shoe too much for this tutorial, but it's good to have there as additional imagery. Uh, my main advice would be always overshoot, never undershoot. It's a lot easier to delete extra images and to make images you never took in the first place. In addition, you want to shoot on an overcast day and that is critical for outdoor scans. This, if you've got the sun casting shadows across something, those shadows will get baked into your model and then it becomes really difficult to relate it yourself in your CG application. So remember to shoot in the flattest, most neutral overcast light that you can, the next step up from this, of course, it'd be an a studio where you have a lot of light control, but for today's tutorial, we're just going to talk about this sort of entry-level shooting with a cloudy overcast day.

Patrick Letourneau (03:32): The application we're going to be using today is reality capture reality capture is a really great multi GPU accelerated Kuda application. Probably one of the fastest 3d scanning apps you're going to find. And they have a very unique licensing model called paper input, where you can download this application for free and use it scan all you want. And you only pay upon export. The charge is based on the input megapixels of the images that you're scanning with. So a bunch of really high res images is going to give you a more expensive scan than a bunch of Lorez images. So if you go ahead and download reality, capture, create an account, we'll just hop over to it here. And I'm going to go ahead and drag in all of my processed images that we captured earlier on the iPhone. And we're going to see that they're all in here in reality capture.

Patrick Letourneau (06:23): And 22 minutes later, we have ourselves a pretty decent looking scan to find just orbit around this a little bit with right click. You can see there's a bit of noise in some of the smoother areas, but that's to be expected with a cell phone based scan. If you have access to a DSLR, I'd highly recommend it you'll get much cleaner scans. And the capture process will be quite a bit easier. Um, but seeing inside looks like we got the laces captured. We've got some of the inside walls, which is great as I wasn't. Super-duper focusing on those with my capture session more on the outside here. Um, the issue with this is twofold. One it's 15 million triangles, which is just not a fun number of polygons to be working with in any application. And two, we need to do a little bit of cleanup. So we're going to go up to the reconstruction tab here and in the tools area and the selection area, we're going to start by grabbing this lasso. And I'm just going to line up here and click and drag to grab our stand. And then we're going to hold control to add to that selection and just kind of orbit around. It looks like we've got to capture a little more here, so add to that selection.

Patrick Letourneau (07:42): Okay. So we've got our stand selected here and I'm just going to go up to the tools panel and we're going to click on filter selection, and that's just going to do exactly what it sounds like. And it's going to delete whatever we have selected. Once that deletion is done, we can see that we have a shoe without a toilet paper roll underneath it anymore, which is great. The next step is going to be to close up the holes in that model. And we're just going to hit the close holes tool for that. And any time you hit a tool in reality capture that has some sort of options, the dialogue is going to pop up in the bottom left here. This is sort of like your cinema four D attributes manager. And so we're just going to hit close holes and just like that, we have a mesh without holes on the bottom.

Patrick Letourneau (09:02): So the process of reducing the complexity of this model to something that's a little more workable is done right here, inside reality capture. If you were to rig this thing and you need it, perfect quadrangular edge flow and topology, maybe you'd bring it into something like zebra, shh, and uses the refresher on it. Or you could use instant meshes, which is a great free tool. Um, now integrated in cinema 4d. In fact, for performing quadrangular re typology, but since we're not going to be doing much with this other than rendering it, I'm going to say that just triangles will be fine. So we're going to go up here into the tools pallet once again, and we're going to select the simplified tool, simplified tools going to pop up here in the bottom left, and you can see that we can set an absolute or relative type of reduction.

Patrick Letourneau (09:51): We're going to stick with absolute for now. And we're going to say 250,000 triangles is our target with that set. We can just come down here to the bottom and we can hit simplify with our simplification done. You can see that our model is now quite a bit less detailed than it was before, but the spirit of it remains. There are no holes in it, no huge issues. It is however feeling a little bit noisy. And especially when it comes to breaking down normal maps and transferring the quality of the high-risk model onto this low-risk model, we're going to want something that doesn't have all of these sharp 90 degree edges on it. Those just never turn out great. So what we're going to do is we're going to go up to the smoothing tool here. And once again, it's going to come down to the bottom left at the top of our panel, and we're going to up the smoothing iterations to five, just because this is a pretty noisy model. We'll leave smooth and wait, where it is, smoothing type of noise removal, all good. And now we'll hit smooth. As you can see, you end up with something a little more melted looking, but this will be a much better target for reprojection of our textures. So also be a much better target for baking note or normal maps

Patrick Letourneau (15:57): Moving on. Now we've got our shoe here inside of cinema 4d. I've just dragged and dropped the export OBJ into the viewport. You can see this is pretty low Rez here, feeling really nice and nimble and quick, but down a little plane here. So we get some reflections from the light and put down a rich shift dome light with my favorite Maxime Roz HTRI next step is just going to be to create a Richard material and we'll drag that right to our shoe with a material selected, hit, edit trader graph. We're also going to open up the rich for interview here and we'll hit play.

Patrick Letourneau (19:12): And so a great way to cheat a roughness map or a specular map is to, first of all, we're going to disconnect our diffuse color. We're going to come into our object here and we're going to manually set it's color Dow all the way down to black so that we can see just the reflection. So next thing we're going to do is put down a red shift ramp node. We're going to wire a diffuse through the ramp, and we're just going to preview this ramp node on the surface. Um, you can do that by going to tools and connect note to output. I have mine hotkeys to V which I strongly suggest you do because it's a huge quality of life improvement. So looking at this ramp texture, we can see here, um, that we've got black to white. Um, so with the roughness map, you want the rough areas to be white and you want the shiny areas to be black. 2ff7e9595c