Baking Perfect Texture Maps Using a Cage | Blender 2.8

hello in this tutorial I'll be showing you how you can get perfect bakes using a cage so that's perfect normal and cavity maps using what's known as a cage to help your bakes it's worth pointing out that this tutorial is not for beginners and you should have a general grasp of baking texture maps if you haven't got that yet then look at my tutorials on baking once you've understood the principles of baking then baking with a cage will help you get perfect Maps I'm using blender 2.8 but it's exactly the same process in blender 2.79 so first of all what is a cage well I'll use this Photoshop file as an example so let's say a 2d version of my base layer looks like this my rock or something like that so there's a 2d to the cross-section of my model okay did you forget this layer and just change its color to blue so now I've got that one right on top of the other one I just don't do that and that's normally how we bake if they are perfectly on top of each other it should be okay but because this is slightly lower poly it may be that your mesh is very slightly out and away from your higher poly and it's those differences that cause problems in our bake what happens with baking is that anything outside the mesh like this the high poly that's in red that might cause glitches and that's where you need to turn the Ray distance up so that it catches these bits that are slightly outside however when you've got a cage which is my yellow one now what you do is you scale your bake up and make sure it completely surrounds your high poly mesh so you can see those tiny bits of red in there but there's none sticking out at all so the red is my high poly original the blue is the low poly that we're baking to but the yellow is the cage and it's completely surrounding my object that way we use the cage to guide our rays as it were but the blue keeps its shape you can actually just scale up your blue your low poly so it's outside of your shape but you might lose detail when you do that that's why we need a cage which is exactly the same as our low poly just scaled-up so let's do this in blender so here I am I've got a high poly model here and a low poly model let's just look at the low poly first and I've taken this out to instant mesh and it's done an okay job which is about 4,000 faces it's still fairly high to be honest and I'm sure you could easily reduce this even more here's my high poly version just hide the low poly and show you the high poly I had to reduce this as well so it's only over a million faces and sometimes your high poly is a bit higher than this it depends on how well your computer handles it and I'm screen recording at the same time and I want to be quick so I don't want any issues there so I've reduced this but you might have a higher poly so if I grab my low poly again let's make that visible you can see there's parts of my high poly that overlap my low poly so when I bake now I'm going to have lots of little glitches which I'll show you shortly but first let's make our cage so with the low poly selected we duplicate it shift D and I'm going to call this cage so got three objects high poly low poly and cage the cage and the low poly must be exactly the same in terms of faces and vertices otherwise it won't work I'll just hide my low poly and have my cage selected then I'll go into edit mode with this and I'll scale it up by the normals so that's alt s and you'll see what happens I'll press alt s and I'll actually move my mouse slightly and there's huge increments when you do this so hold down shift and I want it to just overlap my shape so I'll go to about there and I'll have us hunt around and see if there's any issues anywhere kind of looks like there's an issue there but I'm not sure what's going on so it's completely surrounded by mesh that's the quick way of doing it when you've got nice sort of spherical objects like this otherwise you might have to go into individual vertices and pull them out manually if it's not completely covering your mesh and there's any sort of high poly bits that are pointing through any bits that are pointing through will show errors in fact there's one just there so what I can do so I can click on that face zoom in on it and grab it and pull it out let's just quickly hunt around for anymore and I think oh there's one down here and that is some bad topology there I'm not going to fix that just because of time because I have to fix it on my low poly as well so I'm just gonna grab this and pull it out and hope for the best I'm surprised in some mesh did that okay so now I'm ready to use this as a cage so let's bring back all our objects and set up the materials for my low poly normals so I'm going to go to the UV editing layout pull out the screen and change it to the shader and I'm going to create a new map and call it rock normals increase the resolution to 2048 by 2048 and I don't need the Alpha and press okay I'm just going to call this material low poly and make sure this material is in my shade of shader editor so shift a texture image texture let's change it to non color data now and make sure it is my rock normals so now if I select my high poly it has the same texture because they've all got the same texture to start with and it's a good idea just to give it so new texture so we call this rock high or HP and just make sure that our rock low poly has the low poly texture so there's my rock high poly and rock low poly and they both got a different texture that's fine and the cage doesn't need any texture okay so rock high poly is selected first then the rock low poly and let's go to the Baker panel under the render settings you can't do this in evey at the moment so we've got to be in cycles and let's go down to bake and let's go to a normal map now in blender 2.8 you sometimes get glitches but that's usually that just your bake won't work and sometimes you just to deselect everything reselect and then try back again so I'm going to select it to active which is the selected the rock high-poly to the active which is the rock low-poly selected last I know it selected last because that's the texture and material I've got over here and we're going to tick cage now we could obviously do Rea distance that's what I was talking about earlier so let's keep ray distance to zero and do it without a cage to start with and bake and I made a mistake I forgot to unwrap my object so let's just quickly do that now into edit mode select all you to unwrap Smart TV project and I'll just make sure there's a bit of boundaries press okay okay I'm just back from a crash because I tried to unwrap the high poly object by accident now I've unwrapped the low poly object I'm ready to go into the baking panel so let's select the high poly the low poly into baking with cycles and we were going to test selected to active without the cage so let's try that and let's actually try it with the norm app this time okay I'll tell nothing well so let's try that again no bet normal map baking is fairly quick or what should be anyway and you'll see any errors appear it down here now you can see there's lots of errors because like I was saying there's an overlap and I haven't put my ray distance up in this case I'll put up to one and just check what that's like and that's giving us a nice clean bake so in this case we can get away with just using a ray distance of one which sort of extends the boundaries of any overlap but if you want perfect bakes and you're still getting problems with your ray distance being turned up that's when you need to create your cage and in general a cage is very slightly better at calculating the angles piece it's better to point your raise inward than it is to increase the raid instance so if you feel like your normal maps aren't really cutting it then a cage is for you so let's take the cage option we still have a cage extrusion option here but I'm going to turn that down to naught and that's if you're getting any slight which is that's where you might have a bit of overlap but let's find our caged object and then once more hit baekje and there we have it a perfect normal map once again so now you can use the same process on your cavity map which I'll go into in the next tutorial so that's it for me I've left a few mistakes in there but hopefully you can learn from those and not make the same mistakes as me as well thanks for watching and I hope this helps

Channel: Grant Abbitt

Views: 82,073

Keywords: understand, texture, paint, how, to, learn, blender, tutorials, 3d, art, graphics, game, material, guide, easy, normals, cavity, maps, baking, 2.8, blender 2.8, 2019

Id: nJ0PM7m9TJc

Length: 9min 21sec (561 seconds)

Published: Sun Feb 03 2019