Bodyslide: Guide and Tutorial
What is a "BodySlide"
Bodyslide is used in tandem with Caliente's Beautiful Bodies Enhancer (CBBE). CBBE does a number of things: First, it replaces all the skin textures of the stock NPC models. It must do this for all character models, including the Player character as that is how Skyrim is designed. Some other mods may replace the character model and CBBE can then just modify that one model, but that is beyond the scope of this document.
More importantly CBBE replaces the shape of what female NPCs look like. This goes beyond simply what their skin texture looks like but how large their shoulders, hips, and 'endowments' are. And even more importantly this can all be modified in CBBE's partner program, BodySlide. By itself CBBE does a lot - namely replacing skin textures and changing the default female NPCs bodies to whatever you chose in the install. But Bodyslide lets you customize body proportions yourself.
Outfit/Body - The key to Bodyslide
At the very top of Bodyslide is the "Outfit/Body" dropdown. You can have hundreds of these, but most importantly each one of these will generate a specific ".nif" file. nif files are specific outfits within the game that will be replaced when you generate a nif file from Bodyslide. Note while Bodyslide can replace in-game assets it can also be used to generate .nif files not in game but used by other mods, for example Player Specific models and races. "Outfit" should be thought of loosely. It does not mean a specific costume, dress, or armor. It is a 3D model ranging from hands, gloves, shoes, helms, but most commonly armors/body and leg clothes (never faces/heads when it comes to Bodyslide), and most importantly the 'naked' body. By default if your character has no armor on they will be given a set of underwear and won't actually be naked. This '.nif' model (which corresponds to the torso) is called "femalebody_0.nif" (or _1.nif which we'll get into). Bodyslide, and CBBE by default, let's you replace this model with an actual naked model by generating a new femalebody_0.nif. This is done by clicking 'Build' once you've picked an "Outfit/Body" that corresponds to that same model. Unfortunately there's no way to tell from the dropdown which nif model is being replaced but it's usually obvious based on the name. As a consequence you may very well have several Outfit/Body options in your dropdown that all correspond to the same .nif model. One of the most common questions in Nexus is why their 'naked' model still has underwear. Most likely this is because you selected the "Never Nude" option when installing CBBE, which replaced the naked female model ("femalebody_0.nif") with one that has underwear. In the image below most of these models, when "Built" replace the same model with a different looking model. The NeverNude models all have underwear.
Sliders and Presets
We will talk about the Sliders first as they will relate to Presets. Once you've picked a Outfit/Body from the game you want to replace, you can now make anatomic changes to it as you see fit. The Sliders are mostly self explanatory. Slide them up and down as you choose to make whatever proportion bigger or smaller. However there are a couple nuances. First, there is a left and a right slider. Why two sliders for one model?
The answer is each NPC in the vanilla game is given a 'weight' from 0-100. This allows for some diversity in the shapes and sizes of various NPCs in the base game. The left slider will determine the shape/size of the smallest NPC in skyrim (size 0) and the right slider will determine the size of the biggest NPC (size 100). This is what the "name_1.nif" or "name_0.nif" means; it's the separate models for characters between 0 and 100 weight. Do not confuse these weights with weights of skeletons used for physics which is completely unrelated and will be discussed later. If a character weighs something in between 0 and 100 the game will accordingly pick a size in between the 0 and 1 .nif model.
The sliders you are presented with for each Outfit/Body are custom made by whoever created the uploaded the Outfit. In CBBE's case, Caliente imported the vanilla outfits into a separate sister program called Outfit Studio, which allows creators to make these BodySlide sliders for users to play with. What this means is sliders are different for different downloaded packs. Not only are there sliders for different sizes of body parts, but some creators even let you delete (or 'zap') entire components of the armor including bags, skirts, etc. This is why you'll often see CBBE outfit packs with different names, such as TBD (Touch of Dibella), UNP, 3BBB, and many others. The CBBE part means the models were created in Outfit Studio and can be edited in CBBE, but the created models may use different sliders than the default sliders. Note many modders do use the default CBBE sliders and will Group (see below) their Outfits accordingly. Not only can the sliders differ, but the starting model is also different. Each creator that makes a Body/Outfit for Bodyslide has "zeroed" (all sliders to the left) the model you start with. From this zeroed model can then make changes. This model will be different from others even when referring to the same .nif file in game. This is why you have a separate slider for "Smaller" and Bigger" rather than the slider starting in the center and letting you go up or down. The "Preview" button helpfully shows you what effect your sliders will have in game.
This is essentially what "Preset" is, the dropdown below Outfit/Body. A Preset is simply a saved arrangement of sliders. All default models start the sliders to the left, and a Preset is a saved configuration for both the 0 and 1 model of various slider positions for the different body parts. Presets are simple to make and you can delete any you like (defaults included). Bodyslide would still work, but you would have to do all the sliders yourself (not recommended). The names of all these Presets are just descriptions (Curvy, Slim, SevenBase, Fetish) and are simply configured sets of sliders applied to the various Outfit/Body models. You can and should make any Presets you like.
Presets are very helpful because they allow you to set the sliders in a way you find most appealing and save this configuration for use later. This is easily done by using the Save/Save As function when you're done playing around with the sliders. It is very important to understand the difference between Presets and Outfits/Body. Outfits/Bodies are specific game armor/clothing/bodies models imported from Skyrim that someone else has modified and added to CBBE for you to alter. Presets are your configurations you can make to those models (which is really the point of Bodyslide). Models don't require Presets to be used, but a Preset always has an associated Model. You can and should make your own Presets, but Outfit/Bodies are downloaded by users (but can be made through Outfit Studio, much more complicated than BodySlide).
The other benefit of Presets is it let's you set a specific Model's body proportions, and then load up a different Model (say, a plate armor and a barkeep clothing) and see how the same configuration looks with different types of clothing. This is easily done by just picking your saved preset after you've picked a different armor.
You might notice that a Preset isn't showing up on a given Outfit/Body. Why? Different Outfit sets made by different people will have different sliders, it means Presets from one Outfit cannot be easily applied to another sets. If you try to use a Preset on an armor that doesn't share the same sliders, likely nothing will happen! This is why when you save Preset it asks which Groups you want to apply it to. Obviously only apply it to Groups that share the same sliders.This will prevent you from picking a Preset for an Outfit/Body that doesn't even use those sliders. This is a good time to talk about Groups.
Groups help organize the large numbers of Oufits/Bodies you may acquire from Nexus into collections. Some of these work properly together (ie. those with CBBE in their model names usually share the same CBBE sliders as the default sliders that come with CBBE) while others have completely different sliders (see Touched by Dibella). Grouping helps prevent you from applying a set of Presets to a Group/Outfit that doesn't even have that set of sliders. Additionally, Groups also help keep sets of armors that belong together in one package so you can easily add them all or can add model that contain physics (see below).
Let's try filtering out some Groups. Click on "Group Filter". While you can type out a name I strongly recommend you select "Choose Groups" as Groups must be spelled exactly to show up and if you want to select more than one they have to be separated by commas and, well, just go with Choose :smile: . Note choosing more than one Group is an "or" function, as in it'll include any Members that belong to any of the chosen Groups, rather than picking members that must in both groups.
You'll see a list of different Groups. You may notice there is CBBE, and also CBBE Bodies, and maybe CBBE Vanilla Outfits. The CBBE group will actually contain all the Outfits/Bodies in the latter two categories. "CBBE Bodies" will only contain the naked (and underwear .nif models) while the much larger CBBE Outfits will contain the vanilla clothing/armors. Why are these separated if they both use the same sliders?
The reason is because Caliente's sliders packaged with CBBE have two preset variations: Normal, and Outfit. The main difference is the bust is more 'pushed up' in the Outfit model, as if the character was wearing some kind of support, which they probably are! By separating these Groups out it'll be easier to "Build" these models, which we'll get to.
Groups are not made automatically, but created via the Group Manager Button. Clicking this will open a window that clearly shows how Groups are defined. Right now everything is greyed out, but click Browse and select CBBE.xml. You should see 2 Groups: CBBE, and CBBE Bodies. Below each you'll see the Outfits/Bodies that each Group contains. Groups are not mutually exclusively and a single model can be added to many different groups. And in fact in this case, both Groups seem to have the exact same 'Members' ('Members' are just Outfits/Body that are now in a Group). Why have 2 Groups with the exact members?
The reason is they actually don't contain the same members. CBBE generates Groupings in the main window based on all the XML files in its folder. If you look in the folder there are usually several XML files, and together the different CBBE subtypes will be more clear (Vanilla Outfits, Dragonborn, etc). As you collect more Models/Outfits they will usually come nicely organized into Groups of their as instructed by the XML files they come with. Models/Outfits that have the same default CBBE sliders will be added to the generic CBBE group AND usually their own Group as well. This accomplishes two things: tells the user that these armor sets use the standard CBBE slider, but also let’s you subgroup them from other CBBE armor sets that have similar nifs.
Back in the main window there is another filter window next to "Group Filter" called "Outfit Filter". This is a simpler but less powerful tool for filtering all the Outfits. It's simply a keyword search. Here you do want to type in the Outfit you're looking for. Try Iron, Fur, or Leather. This will filter out all selected Groups that have any of those terms in the name (this would be an "and" function). While this is helpful for quickly searching an armor Grouping is much more powerful when doing Batch jobs which will be explained below. Note you can build Groups from the Outfit Filter by selecting it again after you've done a search and creating a Group ("Save Outfit list as group")
Up to this point, we've skirted around the large, Build Button. You can do anything you want in Bodyslide and nothing will happen in your game, until you hit Build. What does this do exactly?
Build does 3 things at once: 1) It checks to see which Outfit/Body you've picked. This always corresponds to a single, specific armor/clothing mesh/.nif file. 2) It then looks at the slider configuration you've made (or perhaps selected as a Preset, it doesn't matter), and 3) it will then create 2 files, the "xxx_0.nif" & "xxx_1.nif" that get added to your Data folder (or Mod Manager virtual folder). It is this file that replaces all those armors/clothing in the game to the proportions as you've selected.
There is a bit of added functionality if you hover over the "Build" button. Holding CTRL will add the nif files to the "working directory". This does not add the files to the game at all but exports the nif file to the BodySlide folder for editing with other programs. It is not useful to us. Holding ALT and click Build will delete the .nif model you are adding if you no longer want it. I find it of limited utility.
One of the most common questions on the forums is why does my model shape inconsistent when going from naked to wearing clothes. The reason is because characters don't actually 'wear' clothes, they replace their entire bodies (torso, etc.) with different models. In order for your character's to be maintained when dressed vs. naked, each model has to be changed to the Preset you selected. The same Preset you used to generate femalebody_0.nif must also be applied all other Outfit/Body models. This means every single armor, clothing outfit, etc. must be "Built" with the chosen Preset.
This is where Batch Build comes in; the powerhouse behind BodySlide. Build works well enough, but there are hundreds of models, clicking on Build for each one would take forever. Batch Build solves this.
Like Build, it: 1) Checks the slider configuration you've made, but then instead of checking the single Outfit/Body you've picked, 2) it checks which Groups you have chosen (next to Outfit/Body, in the Group Filter Window), and 3) creates two .nif files for each Outfit/Body from all members in the selected Group(s). You'll be prompted with the complete list of all the filtered Outfits you can add your Preset to when you click this button.
If your groups are managed well you shouldn't have many, if any, Outfits/Bodies selected that refer to the same .nif file. Obviously you can't replace the same model with two different meshes/Bodies. If this does happen, BodySlide is kind enough to bring up a second window asking you to resolve the conflict; namely pick which model you wish to choose.
In the above picture after clicking "Batch Build" BodySlide informs me that several of the filtered Outfits are trying to create the same file (femalebody_0.nif). I must pick which model is going to get the Preset to be built into the game.
Like the Build button there is some added functionality with holding CTRL. This time holding CTRL allows you to pick which directory you want the models to be exported to. This can be helpful if you're finding Mod Organizer isn't putting them where you think they should be. ALT-Click once again deletes a batch of models (the same ones that are filtered).
Once you've learned how to Batch Build you've mastered the basics of Bodyslide.
A small note about Build Morphs (the small checkbox at the bottom): This is only used by another mod called RaceMenu to allow you to change body proportion in game without having you constantly build models and relaunch Skyrim until you're satisfised.
Once you're familiar with BodySlide, adding physics to your meshes is the next big step.
Adding physics always requires at least three important additional Mods: XPMSSE, Fores New Idles, and either CBPC or (less likely) HDT-SMP.
What are these and what do they do?
Very Simply: Fores is the main engine that allows almost any model to be animated. It requires a 'skeleton' (this is not a literal bony skeleton but an invisible kind of wireframe use for animating) that is then told how to move by other modders. All models have some kind of skeleton, but XPMSSE adds additional 'skeleton' bits to different game models that otherwise don't exist. This could be new limbs, wings, or in our case breasts/butt. Don't ask why breasts have "bones"! CBPC and HDT-SMP are physics engines that use the skeletons, add weight to them, and make them respond to gravity/movement.
What does this have to do with Bodyslide?
In order for a model to be used by CBPC it must have a Model that contains a skeleton with Breast/Butt components or it simply won't animate. Practically, this means any .nif meshes (Outfit/Body) you Build must have these skeleton bits in it. Fortunately Outfit Studio allows modders to make models that have these skeleton bits with with weight etc. to look realistic. However for the physics to work you must only use Outfit/Body that actually contain these skeletons. Unless specifically stated most will not have these physics models. Helpfully, most models will contain in parenthesis (Physics) if the model has a skeleton that can responds to CBPC physics. Importantly, don't add models with physics without the supporting mods, it will cause problems.
Again, Groups are very helpful here. Most modders when packaging their Outfit/Bodies will have included models that are capable of physics and models that aren't and put them in specific groups. When you Batch Build Models make sure you are building the ones that have Physics. A lot Outfit packs will have Physics for cloth garments, but not for metal as it'd be unrealistic for metal armor to be bouncing around. You might see only one version of a metal armor but two (physics and non) for cloth.
Most of these extra physics packages have their own readmes, descriptions, compatibilities, and Fores New Idles requires the running of an executable. Going over this is beyond the scope of this instruction.