PhotoScan Guide Part 3: Natural Environment Scanning

hello and welcome back today we're talking about environment scanning before I begin I would like to mention the works of Christoph Schindler and Nicholas brunet the level of detail in their environments has been a constant source of motivation for me and I encourage you to check out more of their amazing work environment scanning is such a complex subject that I decided to break this up into two videos this video will focus on natural environments and the next video will focus on man-made environments and that way we can focus on everything without having to sit through one giant 25-minute long video and to be clear I'm focusing on 3d scanning for visual effects if you're scanning for 3d printing or surveying a lot of the information here is still relevant but you might do some things differently and that being said let's get started when looking at the environment you want to scan ask yourself two questions can this be scanned and if so how much of it do I want to scan now technically just about any place can be scanned but we want clean scans getting a clean scan from a pile of rocks it's gonna be a lot easier than getting a clean scan of a dense forest or a snow-covered mountain so decide if it's even worth your time first as for how much of it you need to scan depends on what the camera sees if it doesn't show up in your final image or film it doesn't need to be scanned less area you have to scan the small of the details can be in your final model all environments fall under one of two categories that I've made up occluded and non occluded occluded environments are places like forests grassy plains deserts with lots of cacti places where you have all this stuff in the way of the terrain usually plant life the stuff that makes getting clean scans a lot harder non occluded terrains on the other hand are relatively easy to scan these are places like mountains barren deserts rocky beaches places where you have a clean unobstructed view from the camera to the terrain and if you want clean scans you have to take a different approach to shooting your images depending on whether the environment is included or non occluded will focus on non occluded environments first and what better place to start then at the foothills of the great Florida mountains of course Florida doesn't have any mountains so we'll just go to the beach instead with no occluded environments you can treat everything as one big object and scan it all together the way I like to work is pretty simple a shootin manual so my exposures stay the same and just gradually move around the subject shootin passes so you get rows of images from multiple angles if I'm shooting something big I like to use my wide lens which is a ten to twenty millimeter Sigma if it's bright enough I like to shoot at f/8 to maximize image sharpness orient your camera to maximize the space the subject takes up in the frame sometimes you'll need to watch out for your shadow and avoid adding footprints into your scanning area as you work if the environment you're capturing is mostly horizontal surfaces you'll want to shoot downward predominantly if it's mostly vertical surfaces you'll mostly shoot from the side again this is to maximize the size of the environments features in the frame all right you just shot a wide path of the environment that might be all you need to shoot depending on how detailed you want the mesh to be texture maps can also hide a lot of mistakes individual effects all that matters is how good it looks not how good it actually is but if you do need more detail shoot a second pass of photos this time getting closer to the environment the more time you put into shooting your source images the better your results can be as long as you don't shoot more images than your computer can actually handle if that is a problem one thing that can cut down the number of photos you have to shoot is getting a sharper lens the resolving power of your lens is more important than the megapixel resolution of your camera some of the best scans I've ever seen have come from a camera with just a six megapixel sensor jean-marc rouille a captured these using a Konica Minolta dynex 7d and often shoots less than 100 images per scan now that's a tyre scan you can take home to mom a sharper lens will benefit every type of scan but especially in an environment scanning where we are sometimes dealing with very large areas a sharper lens is a huge help sharper glass means more detail captured in each image which means fewer images needed overall now if you're dealing with a really big area it's easier to use a UAV to shoot your images if you have access to one I don't but I do have a GoPro which John and Mary bought me for Christmas if you are using a GoPro or a similar type of camera you may need to correct for the barrel distortion of the lens if you generate your scan from GoPro images straight out of the camera you'll get distorted meshes this trestle is straight in real life but came out curved in photoscan undistorted images is simple if you use Adobe software this video will help you there's also a program called PT lens which can be used small cameras like these are also great if you're working in an area that is very difficult to navigate just stick the camera on a UAV and shoot from a distance a GoPro is great for cheap fun scanning but the detail in the images is not great it looks like somebody applied the water color filter in Photoshop so if you desire high quality you'll want to research better cameras for UAV scanning ok so that's how I like to shoot non occluded environments but occluded environments require a different approach tell me what you see here trees grass bushes vines basically this is hell in places like this you can scan everything in one go if you just need raw spatial data like if you're surveying but if you want clean scans that don't look like blobs you have to start breaking down the scene into individual components deciding what can be scanned and what cannot big things like trees rocks and bare ground can give very good results but things that are made up of lots of small structures like grass and bushes and shrubs will never come out clean unless you scan each piece individually these things are better left at traditional modeling or using resources such as the grass essentials kit by Andrew price or the blending nature assets from Derek Goff if you're in a hurry you can get decent results scanning a tree with a wide lens and a single row of pictures if you want really good detail though shoot at least two or three rows of images at different heights you won't be able to get a clean scan of the leaves or the small branches of the upper canopy but you can always extend your scan with traditional modeling using the captured data as reference as you may have noticed I generate most of my scans at medium quality my Barbie PC simply isn't practical for generating at high quality from more than 30 or 40 images but yours very well maybe if it is you'll see a nice jump in quality from medium to high for instance here's a partial tree scan generated on high from just 22 images if you do a lot of environment scanning you'll quickly find it's not the most comfortable activity standing hunched over and looking through a viewfinder will quickly take its toll on your back so here's some gear I recommend to make the task easier first get a monopod it's cheap simple and will make your shot sharper next get a cabled shutter release for your camera this will also make your shot sharper probably and will allow you to hold more comfortable posture when shooting low end high angles it will also enable you to place the camera in positions you wouldn't normally be able to reach otherwise my last basic suggestion is to add a head to the monopod this way you'll be able to set the camera in either portrait or landscape orientation depending on what suits the subject best if you want to get the camera really high higher than your monopod will allow all you really need is a pole PVC wood metal any kind of pole will do to attach the camera I use something called a super clamp strong simple and it's a really versatile piece of kit so I'm not spending money on something I can only use for one thing now if you want to get your camera ridiculously high look in the collapsible poles such as a painter's pole just be careful when putting a heavy DSLR on top of a tall pole and use common sense when shooting outside lastly here are some quick tips the size of your domain or bounding box affects your processing time the smaller the box the less photo scan has the process and the higher you can set the quality level when generating the dense point cloud if you're using a super wide lens check for a vignette in your images it's an easy thing to fix in Adobe Camera Raw depth filtering this could have a section on its own but basically if I'm shooting in a non occluded environment I usually set it to low or moderate if I'm shooting in an occluded environment it's usually moderate or high basically the better your source images are the lower you can set it without getting nasty results you make small things look big needed CG mountain but don't live a mountain look for some big rocks to scan need a big funky looking tree but can't find one scan a bonsai small rocks can look like boulders you'd always tweak the materials of a scan later on to fit your vision remember photo scan is just a tool it's a means to an end some p.m. itself learn to use a software and new and weird ways find a box scan it and then think outside so there you have it my tips for environment scanning part 1 if you have any questions feel free to leave them in the comments and I'll answer them personally and stay tuned for part 2 of environment scanning which is coming soon and as always thanks for watching if you're interested in game development check out the behind the scenes for the unreal kite demo especially starting at the 14-minute mark they have some pretty cool photoscan stuff in there

Channel: ClassyDogFilms

Views: 177,253

Keywords: photoscan, agisoft, environment scanning, environment, tree, scanning, natural, nature, photogrammetry, 3d scanning, photoscan tutorial, tutorial, photoscan guide, photoscan guide part 3

Id: diQAJO4sghQ

Length: 11min 40sec (700 seconds)

Published: Sat Jun 27 2015