Changing the pose of a downloaded stl model in Blender

hi there in this video we're going to show how to Repose an STL that you've downloaded from the internet we'll look at two methods both of which sound complicated but really are not if you follow the steps here first thing we're going to do is delete this queue so we select it press X and delete the first thing you need to do is download a model from internal obviously and I'm going to pick a model that I found on Colts 3D it is an STL and I would import it file import STL this is it Molly so we'll import her it can take a few moments so here she is now she's a the wrong way around so the first thing I'm going to do is align her with her origin point it's probably not necessary but it's a good thing to do so I'm going to make sure the model is selected go to object set origin geometry to origin and then I think we need to rotate them so ah X 90. I haven't done that it's probably worth just applying the rotation this particular model Molly was created by Andrea three DNA and I'll put the link to this model Down Below in the comments should you wish to download it Molly the punk and the most important step with this is to manage our own expectations there are limits to what we can do if the geometry doesn't actually exist for example if hands are in a pocket we can't just move the hand out of the pocket and expect there to be fingers at the end of it also as in this case the feet are attached to the base so we can't just move the legs around off the base can be done of course you can remove the base and you can fill in the bottom of the shoes that's a bit beyond the scope of what we're going to do here in this video however we can do a fair bit so let's give it a go before we do it's also worth remembering that this video is specifically about downloading an STL from the internet and STL files are just a load of triangles basically and they're not ideal for what we're trying to do so if you have a means of re-meshing the model first that's the ideal thing to do but most people don't have a way of remeshing at least a way that works or that they're confident with so we'll just get along without it as a starting point let's see if we can get Molly to point her gun straight forward now to do this we will attach her arm to guides which blender calls bones and then we can use the pose tools that come with blender to move those bones and that in turn will move her arm with them this is called rigging which is quite a complex subject but we're not going to rig the whole thing just going to rig the bits that we need in this case we will just rig her arm so looking at this model there are three parts of the arm that we might move separately in order to get the gun pointing forward we have the gun part which goes up to the wrist we have the wrist to the Elbow area here and we have on the elbow to the shoulder those are the parts that we'll need to point the gun forward I'm going to start at the upper arm I'm going to move the 3D cursor to approximately where I want this bone to go and press shift and right click that moves the 3D cursor there and then we're going to add an Armature a single bone Matt puts our single bone here and we also have an Armature in the outliner this is the outliner now the bone is a bit small in this case but that's okay we'll select the bone or at least we'll make sure it's selected and we're going to edit mode with tab and now what we're going to do is we're going to drag this bone grab the top bit and with G grab the bone and move it approximately where we want it to be now when it goes inside the model of course it's not so easy to see and there's a simple way to fix that if we go to the Armature button here in the properties tab and click that we go down to viewport display and click the in front button here that will make the bones always appear on top of the model wherever they actually happen to be so let's move this around into the right place I'll grab that bit G move it there now notice actually that's actually worked a lot better than I expected but if I look at the model from the top this isn't in the middle of the shoulder so we'll grab it move it into the middle you have to look all around your model to make sure that that bone is approximately in the right place and the right place being between the shoulder and the elbow doesn't have to be perfect okay so now we have that we're going to select the tip of this bone again and extrude with e a new bone down to approximately the wrist now if you look that's not the right place at all but so we have to grab that and move it to approximately where the wrist is as I say you have to look all the way around the model to make sure you have this right doesn't have to be perfect now we will extrude one more with the tip of the bone selected we will extrude to the end of the gun it's pretty bad enough let me grab move it up I think that's good enough okay now we only have three bones in our rig which is going to allow us to move the arm you can rig as much of it as you want and if you want to get really complex then you can add a full rig and do something like this [Music] thank you okay so now what we need to do is get this arm to attach itself to these bones so that when we move the bones the arm moves and the way to do that is to go back into object mode with tab select Molly shift select bones and do Ctrl p and go down to with automatic weights now because we haven't got a complete model here and because this computer isn't particularly quick this might take a little while so I'll fast forward through this bit now we're already in object mode so let's select the bones and then we go from object mode into pose mode let's just say I select this bone you can see it's highlighted in the lovely blue if I rotate that by pressing r see how it moves the gun if I select this bone and rotate that it moves the arm and the gun and then I can rotate the gun as well I can rotate it this way as well if I want now we're only making small adjustments if we make a huge adjustment such as this perfectly possible to make quite an ugly model but it basically will do what we want it to do okay so what happens when we move this bone press R to rotate whoa blender has Associated most of the model poor Molly to that bone so everything's moving and that's not what we want now the part blender that we need to use to fix this is called weight painting even though we're not going to do any here we should still know what it is what blender has done here is to create a Vertex group for each bone now for more information on vertex groups you can check out the quick video linked at the end of this video on what on Earth vertex groups are it has collected the vertices of this area of the model and giving it a name of this bone it's collected the vertices of this area of the model and created a Vertex group with the name of this bone and then for this phone it is selected vertices of all this and given it a name of this bone and blender uses that vertex group to know what vertices to move when you move a bone weight painting is pretty awful in blender and we really don't need to be exact so we're going to modify the vertex groups directly ourselves these ones we don't need to touch but what we will do is modify the vertex group for this bone and just remove all of the bits of the model that shouldn't be attached to this bone now you can do it with weight painting you can actually paint the bits of the model that are affected by this and that will give us more control but I don't think we should be doing it in this video so the first thing we need to do to fix this is to find out what the name of this bone is that's actually very easy to do if you go to the Bone properties which is in the properties tab here you go to the top it has the name of the bone here this is remarkably called bone you can rename it if you want to if I selected this bone it's called bone001 and that one is bound zero zero two we're not going to change those we're just going to have a look at this one so now we know it's called bone okay first we need to go into object mode and then select the model and then if we go into edit mode everything will be selected as is always the case it seems and then we press alt a to unselect everything here is the run the ugly geometry of the model and what we will do is we'll go into the vertex groups which is this little triangle here in the properties tab if we look here there's three vertex groups one for each of the bones and there's bone bone one and Bone two now if I select bone two for example and press select it shows you which vertices are attached to Bone two by Alt a to get rid of that I did the same with bone one it shows you these vertices maybe a bit too many actually but never mind or a to clear that now let's have a look at bone we select that well it's half the model so what we really want to do is to get rid of all this stuff there's two ways of doing it select all the vertices we don't want and click the remove button but I think that's going to be quite difficult because they're everywhere and then maybe individual vertices down here so what I will do I'm just going to do it again I'm just going to start again we will remove all of these verses so everything is selected press remove now it has removed them from the group but it hasn't removed them from our viewport here so now we have an empty group called bone if I press alt and a to get rid of everything we will now paint them in ourselves where they should be approximately this elbow wasn't it now it's easier to turn x-ray mode on over here so we'll do that we'll press C which gives you this little circle which you can increase or decrease with a mouse wheel and then you can just paint on here the reason we had x-ray mode on is to make sure that we get the vertices behind as well I have to be a bit careful when we get up here because we don't want vertices on the back of the body now one of the annoying things with this C option for selecting things is that you can't move the model around you have to come out of it with the right Mouse button and then you can move the model go in Place press C again and then we'll remember that we will be selecting vertices right through the model as well so we have to be careful at what angle we're looking at it we don't have to be perfect for what we're trying to do here allowed us to go down do something that looks about right on the other side of the model probably we'll move a little bit of a armpit there's a perfect example of what I meant I did a armpit over here and because we had x-ray mode on it selected all those as well so I'll just unselect them I can do that with c as well by holding the middle Mouse button down or pressing shift momentous scrubbing over them okay so now we need to assign these to the Bone vertex group and so press the assign button and that should be okay let's find out a ton of x-ray mode off first go into object mode select the bones on the Armature and then we go into pose mode and now if we select this bone and rotate it it only rotates the arm now you will see because this is an STL and because we haven't used weight painting this is quite horrible here and we're going to fix that in sculpting afterwards okay so let's make our point the gun straight forward which is our original aim I might speed this up okay so that's pretty much that we can add bones to other parts of the body if we added some more bones in there and did the control p with automatic weights again then that will work and then you could adjust this arm too but we need to fix this which isn't very good so we're going to fix this with sculpting so I'm going to say we're happy with this pose and we're going to go into object mode select the model and go to object convert mesh and that would apply everything and we don't need the Armature anymore so I'll turn it off now that is fixed I don't actually like it that much but it'll do we're going to fix these and we're going to do it in sculpt mode so with the model selected we're going to go into sculpt mode all we're going to do is smooth these out now you can't do this as it is because the geometry is all over the place as you can see and that's the result of stretching basically an STL so we need to introduce some more geometry in here so what we're going to do is we're going to select the smooth brush here and then we're going to go over to the tool properties click on this button and we're going to scroll down to this din toppo or dine toppo let me select it an error will appear but it always does that so just click on OK and open it now if you've not done this before it's easiest to set this detailing from relative detailed constant detail and then increase the resolution up to well I think 40 is quite good but I'm not sure this computer is going to handle it but we'll try it I'm 40. but what this does is when we use the brush it will add geometry as needed but only in the area that we brush so let's try it we'll turn the strength down to maybe 50 percent and just do light Strokes there you go oh let's see another bit there if you're big into sculpting you can do a lot more than this obviously but I think for this kind of model this would be fine okay so now I'm going to try and do this in a different way we're going to use a method which is actually easier and certainly is easier for just doing this arm but it doesn't give you as much control as doing it the way we have just done this with the bones we're going to use the pose brush and I will start with a newly imported version of this model okay here we are with that new freshly imported model and I have applied the rotation I've been in the first one so let's go into sculpting mode this isn't difficult so you don't need to worry about this it is actually easier in a lot of respects with model selected we go into sculpt mode and then we're going to select the draw facex icon amass this one here so we select that if you hover over the gun and press shift W and move the mouse up you'll see it draw in a color that may not be the same as this a face set it's called along the arm I'm gonna keep going so we get to approximately the top and now we're gonna draw another five set to go up to the Elbow we hover over the gun shift w for some reason there's a pause before it actually does anything but then we go up to the Elbow down there and then we add one more shift w and we go to the rest you can really see there but that was close if you find that the face set is merging with other bits of the model when you're doing this if you press 2 while you're dragging the mouse up it will follow the topology at least you'll try it soon these face sets are okay but they're not great the way to increase this green face set here up to the wrist is to hover over the green press Ctrl and drag now notice it doesn't work this I'm 100 sure is a bug it does work most the time and it doesn't work on this model and I have seen it on a couple of other models but it doesn't work but it's easy to fix you press tab which takes you back into edit mode and then you press tab again which takes you back to scope mode now hover over the green press Ctrl it works so now we can draw in that face set up to the wrist looks okay I think it doesn't have to be perfect and the blue one looks okay actually but this one is a bit messed up we're going to make it look a little bit like the vertex groups we did before we will grow the face set a bit here up to the top of the shoulder I think you can adjust the size of the mouse pointer here by pressing F do big bits or you can do little bits if you zoom in you can do some very fine grain control remember to zoom over the face that you want to extend First Press Ctrl and you can do some very nice control if you want to now there is no option for reducing the size of a face set which sounds pretty boring to start with until you find out that no face set equals a face set so if I go in here and hover over the no face set and press Ctrl it will extend no face sent over to the face set effectively just rubbing another one you've got but let's do this I would suggest not affecting something like this article of clothing because you don't really want that to be deformed obviously if you're doing the model yourself in scratch you absolutely would want it performed but we're trying to do something that the STL file wasn't really designed for but anyway that's about right now one thing I do like to do is I like to make these a bit smoother I don't think it's really necessary but it might be it makes it look nicer if we scroll down here to the mesh filter select that go up to filter type and change it to relax facex and if I drag my mouse across the screen with a left Mouse button held down it will smooth up let's face it really unnecessary okay so what we're going to do we are going to go to the pose brush next which is this icon here okay and now again we should be in the active tool tab this one and then if we go down a little bit to the rotation Origins change it from topology to face sets and now if we move our mask pointer over the gun you'll see one single white line which goes from where the mouse is to the end of the face set so now if I hold the left Mouse button down I can move the gun gentle movements because it's a little bit sensitive it has to be said I will control that out of that just for now you can do this part of the arm by the same method or if you change these pose ik segments over here from one to the number of bones you have in our case three and notice that you get three lines and you can move a whole lot together do that again if you're gentle with this and careful with it you can do a very very good job now we still have that same problem here not bad actually but again that would have to be fixed in the same way as we did with the last method we used now you can rotate as well let's put this pose ik segment down to one again but let's just rotate the gun if you hold the control button down prototype nope if you don't have the control button down it will move from side to side control button down will rotate so there you have it if you want to learn something about cutting up and keying a model in blender then please click the video on the top right or you might prefer the video on the bottom left of your screen I don't know what that will be but I hope you enjoyed this video if you have any questions I do answer them please feel free to put them in the comments below and thank you for watching [Applause]

Channel: Not Very Good Guy

Views: 18,296

Keywords: stl, posing an stl, blender, changing an stl

Id: 7P5rdtzc18E

Length: 25min 25sec (1525 seconds)

Published: Wed Apr 12 2023