Blender [2.8/2.9] Character Weight Paint: #3 Weight Paint Workflow (beginner tutorial)

this is the third and probably final part in this mini series about weight painting here we'll finally get to paint bone weights and at the end of the video i'll show you how to paint your rigidify characters so stay until the end if you're interested in that okay i'm starting from the same scene that we used in the first two videos download link is in the description also i'll set my shading to solid and color to single i already explained that in previous parts before we start painting it's important to explain how blender's armatures are organized here i have a blender armature or a rig and you can see that it consists of these gray shapes that we call bones but also includes these special shapes or widgets so in general the bones actually deform the mesh and the widgets are used to drive or simplify the movement of the bones but the widgets do not directly deform the mesh if i go to pose mode this star shape here is the root and it moves the whole rig with it these circles and at the ankles are ik controls and here we have the pelvis control these are pole targets and everything else is a normal blender bone it is important to understand that all of these custom shapes are actually bones if i go to edit mode if i go to edit mode you'll see that for example the pole target has become a bone shape the ik target as well the root as well and so on and so forth this is a bit different from other software where the widgets are made from empties or dummies or whatever they may be called in that software so how does blender know which bone to use for deformation and which are widgets this is controlled by the deform property in in the bone tab so currently i have selected the root and it has the form turned off maybe if i switch to pose mode that would be easier to see here we have a widget the root and it has the form off on the other hand these legs here have the form checked the spine also has a deform checked the arm as well but this pelvis control and the ik target have it unchecked so if the form is checked then blender know that this is a bone that will be used for deformations and if not then blender assumes that this bone has another purpose by the way this is almost the exact rig that we created in my video called intro to blender armatures so if you did that exercise you should understand these things and if you're new to rigging then i recommend watching that video and finally you may notice that a lot of the deforming bones in in the rig can be directly manipulated that is not a problem although in a more complex professional rig the deforming bones tend to be on their own layers and widgets are used to animate and pause the rig that's how rigify does it for example okay finally weight painting there are several ways to add the vertex groups that will be used by the deforming bones one way is to add them manually but that's just crazy so let's forget about that if i select my character and then the rig and press ctrl p there are three options here that will create these vertex groups that i need automatically and those are with empty groups with envelope weights and with automatic weights now each of these options when you click them they do three things simultaneously first they parent your character to the rig second they add the vertex groups and third they add a armature modifier the only difference is that empty groups create empty groups as the name suggests whereas envelope weights and automatic weights attempt to create some sort of automatic weighting for your bones and automatic weights is by far the better option it creates better results almost every time the only problem with it is that sometimes it fails with an error it is something like bone heat failure or something like that a lot of people are experiencing that area and it has to do with your mesh if your mesh is a little bit messy or um sometimes the scale may be the problem then you may get this error and so in those cases you may try envelope weights but generally i find the results that envelope weights produces so bad and inconsistent that you might as well just start with empty weights i mean empty groups so my recommendation is to always start with automatic weights and then tweak the weights where they look bad i know some people prefer to start with empty weights and then paint everything manually and that's totally fine but i'm going to choose automatic weights and that's what i do in general okay now i can switch to weight paint mode if i select my mesh and go to weight paint mode and then i can go to object data properties and then select the vertex group that that i like and i can start painting okay but i'm going to undo here and please don't start painting yet because we need to set some of these additional options it is extremely important and also working this way is extremely cumbersome i mean you have to go over here and choose your vertex group then go back to the the three view and then start painting and then choose another vertex group that is very very um tedious so blender has a better solution i'm going to go to object mode select the rig then i'm going to shift select the character and then i'm going to switch to weight paint mode now when i control click on on one of the bones first blender selects that bone and second it activates the vertex group that is associated with that bone and that is just very very cool and not only that as i have this bone selected i can press r as normal and i can rotate my bone that allows me to see the deformations of my character as i paint the weights so we are in this weird hybrid mode the mesh is in weight paint mode but the armature is in pose mode that is just great workflow and the blender developers deserve a thumbs up let's see these additional options and then we are ready to go so first make sure that this symmetry options are off you don't want any of these x y and z to be activated or having any radial symmetry you will almost never use these options when painting bone weights the next thing is extremely important enable auto-normalize in the first video of this series i try to explain what weight normalization is and why it is important for bone weights basically normalize will ensure that your weights don't go crazy i'm going to uncheck auto normalize and now with that arm highlighted if i paint some weights over here at the leg by by mistake then that will create bad uh deformations really weird ones actually and so to fix that error i'll have to completely erase uh these these weights that i painted by mistake manually and that can be difficult to do i'm not quite sure if i erased all of them let's undo now if i turn auto normalize on and do the same thing if i now control click on the leg bone you'll see that these weights have already been subtracted from from that leg and all i have to do to fix that is to repaint my weights over here and they will be automatically removed from that arm so it is much easier to fix mistakes and it's and it is less likely that you'll make mistakes in the first place so really remember this or write it down when you paint bone weights always activate auto normalize that is a must the other important option is x mirror this is similar to to the mirror modifier for modeling for example so you will only need to paint one side of your symmetrical mesh and the other one will be painted automatically to demonstrate i can for example paint the shoulder of this character over here and now if i ctrl click on the other arm you'll see that it's already been painted and if i slide weight all the way to zero and subtract some weights from over here and then right click the other arm the weights have been subtracted already topology mirror is a little bit special sometimes your characters may have symmetrical topology but the topology could be distorted in a slightly different way on each side so this option will compensate for the distortion and even though your character is not completely symmetrical you can still paint it as symmetrical one mistake you should avoid is to use these symmetry options instead of the x mirror if i turn off x mirror and instead use the symmetry mirror in the x-axis and then again i paint the shoulder of this character with weight of one you will see that this weight is being mirrored on the other side but for this bone not for the not for the bone on the other side so now if i rotate this arm it kind of affects the opposite shoulder which is pointless and you never want to do that so let's undo so yeah make sure you don't confuse symmetry with x mirror and blender only has the x mirror option it doesn't have y mirror and it doesn't have have z mirror in my previous tutorials i have mentioned that your character should always face front that is a generally accepted practice and x mira is one more reason to do so if your character is oriented another way you won't be able to mirror your weights you'll have to manually paint each side lock relative and multi paint you won't use most of the time so i'll skip them restrict can be kind of useful and i'll see if i can give you a practical example later and i want to make you aware of a very annoying behavior in blender let's say i set my weight to 1 and my strength to 0.3 and then i paint here if i decide that i don't like this brush stroke that i just painted and i uh try to undo with ctrl z you'll see that not only did my not only did my paint disappear but the settings were reset to their previous state that is very annoying and everyone i know hates it and hopefully it will be fixed in the future but for now we have to work that way and one workaround that you can use is again i'm going to set my settings to something like this since i have positive weight that means that i want to add weights to my bone so i'm going to click in an area that already has positive values just once here for some reason i had the x symmetry on that maybe again because when i press ctrl z some settings over here were reset that is very very annoying let's get rid of symmetry and enable x mirror and now i'm going to lightly click oh my god again okay i'm going to lightly click over here then i can paint in another area and if i don't like the painting i can undo and i can undo without losing my settings so it took us a while to cover all of the basics but now we are done and once you understand these basics weight painting is really just an annoying and time-consuming process but it is not difficult to do i'm going to switch to object mode for a second select my armature and um for viewport display choose stick then again shift select the character and and go to weight paint mode so the whole process is selecting your um deforming bones moving them around a bit and seeing where them there may be problems so here i can see that this arm bone should probably affect the shoulder a little bit more so i'm going to set weight to 1 and strength to something low and paint a little bit here on the back i see that the arm may be affecting the back too much so i'm going to select my spine and paint some weights sometimes i like to turn off the overlays and that will show me my actual mesh and even though i don't see the overlays i can still click and paint if i select the the head i can see that the chin seems to be a little bit uh orange rather than red uh the headbone should definitely be deforming the whole head if i rotate it you see you'll see how the the chin is kind of lagging behind a bit so i'm going to set some highest strength and just paint on the chin i'll paint a little bit on the neck this collarbone should actually raise together with the arm to achieve natural movement sometimes at intersection of bones the blur tool can help you a lot so i'm going to choose the blur tool and just click it in the shoulder area and that will smooth the transition between the arm and the other bones in that area i think i lost some volume from the from the back so i'm going to select the the spine and paint a little bit again now the leg is controlled by ik so i need to control click the ik handle and then the whole mesh will turn this purple color and that means that i have selected a non-deforming bone even though it is not a deforming bone i can still select it and move it around so that i can test my deformations while i was playing around and explaining stuff i did paint way too much weights on this leg so what i need to do is select this left pelvis and paint some weights on it i'm with the drawbrush and as we explained earlier thanks to this auto normalize these weights will be added to the pelvis and spine area but they'll be at the same time they'll be removed from the leg this crotch area is moving way too much with the leg so select the spine and paint some weights over there in this area some of the vertices weren't completely controlled by the leg bone so i painted them a little bit sometimes turning on wireframe can be useful maybe i can blur a little bit here now if you blur too much you you'll get too much of a soft transition which i generally don't like i think especially with these kind of low poly models uh having a little bit of an overlap between the geometries is better than having a deformation that is too smooth so that's the whole process you just keep putting your character in very extreme poses see what's wrong and then try to fix it by applying your weights in a different way and one eternity later you'll have a perfectly deforming character so here may be a good chance to uh to show you what the restrict option does if i enable it and then go to draw tool with weight to one and i'm also going to increase strength to 1 to demonstrate if i click over here in the blue area it won't be affected that is because this restrict option restricts the area that you can paint to the vertices that are that are already part of this group everything that is not yet part of this group will not be painted on you still have to be kind of careful though because if you paint over here at the edge of the vertex group then slowly it will start affecting the other parts of the mesh and you'll get something that is that looks weird i'm going to undo okay and finally let's cover rigify i'm going to go to object mode select the armature go to pause mode select everything and clear transforms now i want to unparent this character from this simple armature and i want to parent it to my rigifi rig and this is something that you may have to do from time to time and it is not very straightforward when we parented this character with automatic weights this function did three things it parented the character to the to the rig it added the vertex groups and it added the the armature modifier so to undo the whole process we have to do three three things i am going to select the the character alt b and i'm going to choose clear and keep transformation then i'm going to go to the object data properties click this triangle here and choose delete all groups and then i'm going to delete the armature modifier and now my character is completely unparented from from the rig i'm going to unhide the riggify rig shift select selected i'm going to parent with automatic weights i'm going to shift select the character and then go to weight paint mode and now if i control click any of these widgets then my character is purple which means none of these bones are deforming walls where are the deforming bones let's go back to object mode select the character and then in armature tab shift click this layer which is layer 29 then shift select the character go to weight paint mode and here we have these bones if i click them i can see my vertex groups and i can start painting and that's it other than that the the process is exactly the same i can select this ik handle move it make an extreme pose then select the back start painting smooth exactly the same thing that's it i hope you learned a lot about vertex groups and weight painting if you like this video please click like and subscribe you

Channel: CGDive

Views: 25,084

Keywords:

Id: 5SLlp3AwShM

Length: 22min 34sec (1354 seconds)

Published: Thu Sep 17 2020