I have nearly torn my hair out with this one, I couldn’t find information about what I was looking for so I figured id post that here.
Firstly you need a couple things
A Mesh or 3D model you are trying to make your character, and Blender/Maya/Cinema4D or any 3d animation software that supports .fbx exports
And the rigged and animated version of your character.
Model Rigging tips.
If you are adding in multiple characters make sure they all have the same rigs so you can reuse the animations created, you also want to keep arm animations separate so you can have two animations overlapping allowing for arm motions to change.
you can use Adobe Mixamo to auto rig a mesh for you if it looks human like, not sure if its paid however it has been very helpful in getting things done faster. (They also have pre-animated files for you)
Once you have an animation made there is a ton of tutorials on how to make animations for characters,
We need to bake the animation otherwise it won’t work.
To do that while in pose mode of your animation on blender, follow this picture.
You will also want to make sure you bake all of the bones, I have IK’s on my model to make animation easier you don’t need to worry about that affected the final result in Roblox as Roblox doesn’t support IK like blender and the IKs will just be deleted.
Once you click OK and then have all of your keyframes baked to the animation tab, you can export the file as a .FBX to your desktop or wherever.
The following will tell you how to import the model and add the animation in roblox
To import the model on roblox go to Plugins, then click Avatar Importer choose custom and choose your .FBX file you just exported.
Next importing the animation is easy, just use the Animation tool in the plugins choose the newly imported model and then go to the IMPORT tab of the animation, choose Import from FBX and use the file we just exported, this is how you will import the other animations you may end up making.
Now you have an Animation added to the newly added rig, so you just need to Export the animation to Roblox copy the ID, and then you are pretty much done.
The rest will show you how to set the character as default.
Inside of the StarterPlayer folder, add a Model object and name it “StarterCharacter” It has to be named that.
Inside of that model take the MeshPart from the imported Mesh that you animated, not the full folder just the meshPart with all the bones inside it.
Rename the MeshPart to HumanoidRootPart
Add a Humanoid to it
You will want to play in another studio tab and go into your character folder while playing and find a script named “Animate” copy that and paste it into the StarterCharacterScripts folder, then change the animation IDs to the exported one to roblox and you are done, you have now set the new character as a custom one.
StarterPlayer should look like this:
If you got questions let me know, I made this because I keep getting people who ask how I did it, and id like a place to send them.