3D Photoscanning - Optimizing Meshroom Photoscans

today we're going to take a look at how to use the mesh room photo scanning tool to generate meshes that are cleaner and more production-ready than what are produced by the default settings if you do the photogrammetry you may want to watch this video by CG geek called how to photos can easy and free he goes through all the basics of taking a set of photos and using mesh room to create a 3d model from them and that works amazingly well but if you're a 3d content creator like myself you will inevitably run into some major problems that can prevent you from using 3d stands in your projects it was hard for me to find information about this so I wanted to share these easy solutions with anyone who is interested first off if you're already an experienced photo scanner and time is short here's what you need to know stop mesh room when it gets to the texturing phase import the mesh from the mesh filtering folder in whatever modelling program you use cleanup optimize an unwrap it back in mushroom use your meshes the texturing input mesh and finish the photo scan so go do it now for the rest of us who want a little more detail let's take a look at some of the problems I'm talking about here's the scene I scanned at a park near my house using the default mushroom settings now look at this this is an amazingly accurate recreation of these two tree trunks and so my first thought looking at this was wow this is something I can immediately start using in my projects this is fantastic until I looked at my material settings and so each one of these material IDs is a separate texture map that it has created for this there are 118 materials for this one object that I need to go through one by one updating every single one of these in order to manage this I have to have one material that I'm looking at and so another major problem that we run into is so this area right here that we're looking at is the area I want to focus on however mesh room has also generated all this garbage geometry so what I want to be production-ready is a single texture sheet but I also want the parts that are most important to be taking up most of that texture sheet fortunately measured lets us fix all this really easily let's take a look at the process okay so like with any photo scan the first thing we need to do is take our pictures and so this is a rock that I found at park nearby that I liked and I thought it would work well for scanning and so I went around it took a bunch of pictures and so let's open measure of application it'll look kind of like this when you open it and let's drag in our pictures so the first thing we're going to do is we're going to create a mesh from this object using mostly the default settings what I like to do is go into the meshing node and set my max input points to 20 million and my max points to 3 million I'm going to be reducing this anyways and I want to get something a little bit closer to 1 million so that works out a little better for my process and then also in this final texturing node we actually don't need textures for this model this is going to be just a model that we work with to begin making the final geometry so the way that I like to do is just set my textures down to 2048 down scale them to 8 and use JPEG so it saves faster and basic unwrap is fine and so the last thing to help it save things where it makes sense is to save our project somewhere ok and save and that will create all the folders where all the meshes and textures will go so that was the easy setup all we do is click start and now we wait now the mesh that we actually want to use is going to be the one that is out put in this mesh filtering node and so once it gets to this texturing phase you can see it's turned yellow it's working on texturing we can actually stop our build skipping the texturing phase will save you about a half hour from your time so if you can catch it there it's a good idea to stop it okay it looks like we're all done that took a little over an hour in 15 minutes on my computer and so this has already been saved to a folder so we don't need to save it now we just need to open it don't close your mushroom project leave it open because we will need to use this later so I'm here at 3d studio max I'm going to start by importing my model it'll be located where you've saved your project in the mesh room cache folder under the final texturing folder but if you are smart and stopped your photo scan during the texturing phase you will find your mesh in the mesh filtering folder it will be the exact same thing except without the textures so now what we're going to do is we're going to clean up this mesh so that it's just the parts that we want so it's kind of this wonky upside down angle right now so I can kind of tumble around but I can't move or scale or rotate it has to stay right here or else measurement know what to do with it when we bring it back in later and so the first thing I want to do is just get rid of all the polygons that I don't want a little trick that I like to do is come over and select my element and just select the rock that I want ctrl I to invert the selection and delete everything else and this will get rid of little floating islands and anything that you might not notice is out there so that everything is one continuous mesh another thing that can sometimes help is using the boarder selection tool and drag a selection around the main part of your rock and just see if it catches anything it looks like mine doesn't so that means there are no holes in my mesh so that's fantastic that means this is a great preliminary scan if there were holes you can use the cap tool to fill them in and so it's looking really good but I like to optimize the geometry just a little bit this is totally optional and it does take a while so if you want to work as quickly as possible just set your polygon counting mesh room with the meshing node settings and you can skip this entirely let's do a pro optimizer and I will calculate that it'll take a while okay our Pro optimizer has finished calculating so I'll go into my material editor and I'm just going to assign a standard gray material to my object so I can see it more clearly okay so it's calculated so we can just change the vertex count I like to go a 60% you can see if I disable and enable that I can't tell any difference between the two so that's nice they're working with a million Poly's rather than two million so I'm gonna convert to editable poly again collapse that down and do one more look over my object just checking for any holes that I don't want to be there it looks like there's a few spots right up top here that I don't like and what I can do with this if I select these polygons right in here and I'm going to grow my selection until those spaces are covered and from there I'm going to add a relax modifier we've almost right 200 okay and that looks a little bit better so now I'm gonna convert to editable poly again and so now what we want to do is add a UVW map to this so let's do an unwrap UVW modifier you can go ahead and take the time you need to unwrap this perfectly for me and just using automatic unwrapping is just fine and so we'll go okay okay so now our object is unwrapped and it looks okay this is not a great unwrap as you can see there's lots of wasted space but it's automatic and it's immediate and so I like that it's good enough for me and so since that worked I'm going to convert to editable poly again and so this will work for my final mesh so what I'm going to do is I'm going to export selected okay so let's go back into mesh room and we still have the same project open and we can get it to use the mesh that we just created if we go to this little input mesh we can right click on that line and go remove and that lets us click on texturing and now we can select an other input mesh and so the quickest way I know how to do that I go into my folder where I put my mesh and if you shift right click you get this option that says copy has path come back in paste it in and then you need to get rid of the quotation marks at the beginning and the end and now it will use our custom mesh and it will project all the textures and bake them on to it and it will use our unwrap as well I also want to use a little bit better textures so let's do this texture size to 8k texture down scale put that back to 1 and I like to fill holes that just fills the gaps in your texture map with colors instead of black and then everything's ready to go so just click the start button again and it will pick up right there and so we'll wait for it to finish making textures for our object okay so the load model button is showing and so we know that our mesh has been saved and so let's go get it and bring it into 3d studio max again I'll reset my scene I don't care if I lose that one that's been exported already and let's import oh yes so now our texturing folder has two garbled jibberish named folders but you can tell which one you need by looking at the date modified and so let's load our mesh import it okay and now this time I'm gonna scale it up and I'm also gonna rotate it so that it's upright and maybe position it so that it's kind of sitting on the ground okay perfect look at that that's looking great let's pull up our material editor and so you can see we have one single material to work with let's go ahead and open our texture here and let's open this in Photoshop I took my photos on a cloudy day so there's already no direct sunlight hitting them it still has a little directionality to it that I want to get rid of image adjustments and use the shadow highlights filter I like to do a hue/saturation adjustment and so this is one of the strengths of using one map right like I only have to do this one time as opposed to that initial model where I would have to do this a hundred times over so this looks the way that I wanted to let's save it you can see if I turn my self illumination all the way up to a hundred on this map we've lost a lot of our lighting information but for a 3d model that's exactly what we want we want to be able to control our lighting through the scene lights instead of through whatever the daylight was when I took the pictures and again if you want to stop here feel free this looks fantastic and it works great and it renders good too I like to go a little bit farther I'm planning to use this model with my redshift renderer and so I'm going to set up a redshift material and duplicate our color texture to also give it some bump and roughness control it only makes a small difference but it reacts a little better to bright lights and it looks just a tiny bit better up close and so there you have it we have a highly detailed mesh with a simple material that we can control thank you for watching and good luck with your photo scans

Channel: TylerGibbonsArt

Views: 45,730

Keywords:

Id: J3esNV0wXAo

Length: 11min 11sec (671 seconds)

Published: Tue Jun 09 2020