hello anime neon here and this video is part of a program called the NSFW tutorial sponsorship so if you want to create NSFW tutorials I'm paying people 100 USD to share their knowledge it's not much but I want to encourage the sharing of NSFW knowledge in the community in this video tutorial I'm going to show you how to add breast physics to models using the cloth physics built into blender I'm also going to show you how to make models collide with the breast then show you some settings to mess around with on the cloth physics to get the look or feel that you want them to have these are the two models that I will be using one large one small this method works on big or small but tends to work flawlessly on small breasts while using it with large breasts tends to be more difficult and needs more adjusting to look good I'm going to start with setting up the big breast model first you need to make a cube go into edit mode and set one face to have a mean crease of one then go to object modifiers and add subdivision I recommend a subdivision of two for small breast and three for large breasts the cube should become round but still have one flat side now that you have the shape apply the subdivision and go into edit mode resize the shape and move it to fit where it should be it won't fit perfectly so just get it to fit the best you can the actual shape I will be doing manually in sculpt mode though there are many different methods of making a cage shrink wrap re-meshing the base mesh and blender add-ons like simply cage that's close enough it's not going to fit any better than that I've made the cage red so it is easier to see through the mesh when manually sculpting the cage to shape the tools I mostly use are smooth inflate grab and elastic deform I start by getting the cage more into shape and then expanding it outside of the mesh and smoothing it back into the mesh occasionally doing a Vertex smooth in edit mode when it is getting really bumpy you can also do this Step At the very start but I usually do it after but now you need to select that flat face and press Ctrl and G then press assign to new group then rename it to pin inside the object data tab now I'm going to show a really sped up version for the small breast model now click on the breast cage go into the physics Tab and click on cloth this will enable it for the cage with default settings that we have to change as a baseline for the settings copy the settings you see on screen and don't forget to set the pin group as the pin we made earlier and here is our result pretty unrealistic and unusable but we can fix that later after attaching it to the mesh to attach the cage to the mesh you need to First click the mesh and then shift-click the Armature of your character both should be highlighted but the Armature should be brighter if that is the case then press Ctrl and P and select parent with empty groups this will transfer all the armatures vertex groups onto the mesh without weights so that the data transfer can be applied properly now add the data transfer modifier to the cage and data transfer the vertex groups as I have done on screen make sure the modifier is above every other modifier before applying or it won't apply properly after applying the cage should move as if it is part of the mesh now you can apply a surface to form modifier to the mesh of the character and select the cage with it or manually enter the name we don't have a Vertex group for the cage to deform yet so let's make one first go into edit mode select the tip of the breast or the nipples then press Ctrl and the plus sign to expand the selection until it covers that breast now press Ctrl and G and make a new group now rename it to whatever you want and put a period at the end followed by an L or R depending on what side you are renaming go to the tools tab then Symmetry and select these options symmetry will not work if you haven't named the groups correctly as you can see what is done to one side is also done to the other side saves us a bit of time and makes them even now try to shape out the weights with subtract and then blur the edges if you subtract too much you can change your brush to mix and try to fix it or press Ctrl and Z to just go back and redo it mine got a little messed up so I'm going to switch my brush to mix and fix it and if you are trying to fix one side make sure you turn symmetry off or you will have to go and fix the other side too now you can input the vertex group you just made into surface to form for the side you have ready now you can bind it and you can finally see what changes it makes to the mesh but the cloth physics still isn't tuned so it's kind of just dangling off her body I added the third subdivision for large breast which helps it a lot but it still isn't pretty now that it is binded we can see what it actually looks like and start tweaking numbers based off that still looks pretty bad even with the cage hidden you can tweak its settings quality steps makes the physics more accurate but it also gives it more Jitter and makes the physics take a long time to come to a rest while mass is pretty self-explanatory but it changes the mass of the vertex of the cage meaning it will move like a heavy water balloon at high numbers keep it between two and four pressure is how much force is being applied to itself from the inside High numbers make the breast very round and balloon-like keep pressure scale at ten thousand and keep fluid density at one thousand lower it to one if other settings are causing the physics to glitch out the shrinking value shrinks the whole cage at the start of simulation resulting in a tighter feeling for the cage as it retains its shape and shrinks pin should be set and stiffness should be zero you can also tweak the force multiplier at the bottom of the cloth settings on this cage the gravity force is set to 0.5 or 50 percent once it moves and looks the way you want that should be all until you want to tweak it for a different effect in the future now we are going to duplicate the cage and its settings and mirror it to the opposite side first add another surface to form modifier to the base mesh now unbind the surface deform then press shift and D to duplicate the cage right click to place it back go to object and then mirror then select X Global The Mirror Has flipped the normals so we must flip it back in edit mode so the physics can work now rebind the original and bind the new cage now that we have two cages we should rename them now I will show you how to add Collision to character meshes while not just making the whole thing a Collider it is much easier if the Armature is in rest pose now press shift and D to duplicate the character mesh now go into edit mode and select the parts of the mesh that you want to collide click select and then invert now delete all faces selected now just add Collision turning single-sided off is usually the best choice don't forget to bake the physics so that the physics are accurate and not tied to viewport frame rate and so you can see the result without a heavy performance hit you can even add colliders to each breast cage so that they can be squished together much sexier than them just clipping and with that we have reached the end of this tutorial good luck and goodbye thank you for watching