Guides

VRoid and VRM avatars

A character made in VRoid Studio can walk into VR Realms as your avatar. VRoid exports VRM, the kit reads FBX, and Blender is the bridge between them. This is the whole trip, step by step, including the two settings that everyone misses the first time.

What you need

• VRoid Studio, free, with your character finished
• Blender 4.x or 5.x, free, from blender.org
• The VRM Add-on for Blender, installed from inside Blender (Edit → Preferences → Get Extensions, search for VRM)
• Unreal Engine 5.8 and the Creator Kit

Budget about twenty minutes the first time. After that it is a five minute job.

Step 1: Export the VRM from VRoid Studio

VRoid cannot write FBX, so VRM is the file you take out of it.

1. Click the export icon at the top right, the arrow between the camera and the three dot menu.
2. Fill in the author and title it asks for. Leave the licence on its default, Redistribution Prohibited. That constrains other people, not you.
3. Choose VRM 0.0 or VRM 1.0. Either one works here, and the choice does not change any later step. VRM 1.0 has the better spring bone system, but no VRM physics reach the game either way: FBX cannot carry spring bones, so they are dropped when you export from Blender, and the Creator Kit builds the movement for hair, skirts and ears itself once the avatar is in Unreal. Take 0.0 if another tool in your chain still asks for it, otherwise 1.0 is fine.
4. Bake the textures. In the export settings, lower the number of materials. VRoid merges the many small material slots into a few atlas textures and writes them into the file. This is what carries your colours through Blender and FBX intact, and fewer materials also runs faster in VR. You will see the result later as mesh names ending in merged and baked.
5. Save the .vrm somewhere you will find again.

Step 2: Bring it into Blender

1. Open a fresh Blender scene. Select the default Cube, Camera and Light and delete them. Every new scene has them, and the Cube is the white block your character otherwise appears to be standing inside.
2. File → Import → VRM and pick your file.
3. Optional check: expand the Armature in the outliner and look for bones starting with J_Sec_ (hair, skirt) and J_Opt_ (ears, tail). Those become the parts that move on their own in game.

Step 3: The scale (Build can fix it for you)

VRoid works in metres. Unreal works in centimetres. When Blender exports a metre scene, Unreal converts it by putting a scale of 100 on the root bone instead of on the bones themselves. Everything looks perfect in every preview, and in game the avatar would be drawn eighty metres in the air. No export option and no import option removes that scale.

From Creator Kit 0.4.23, Build looks for that scale and removes it itself. It rewrites every bone at scale 1 and checks that no bone moved by more than half a millimetre. When it has done so, the Build log says: carried a ×100 scale (an FBX exported in metres) — fixed automatically. So you can export with the default units in Blender and go straight to Step 4.

Build cannot do it in two cases: the mesh has more than one LOD, or a bone is scaled unevenly or mirrored. It then stops, names the bone, and you fix the scale here in Blender instead:

1. Open Scene Properties, the tab with the cone and sphere icon, and expand Units. Set Unit Scale to 0.01. Leave Length on Metres.
2. In the 3D viewport press A to select everything, the armature and all meshes together.
3. Press S, type 100, press Enter. The character becomes a hundred times bigger. That is correct.
4. Press Ctrl+A and choose Apply → Scale.

Step 4: Export the FBX

File → Export → FBX. Blender forgets these between sessions, so check every one each time. They live in different collapsed sections of the export panel.

The folder will contain just the .fbx. The textures are inside it. When Unreal or another tool reads the file, a folder ending in .fbm appears next to it with the textures unpacked. That is a side effect, not a lost file.

Step 5: Import into Unreal

1. Drag the .fbx into the kit project. Any folder works.
2. In the import dialog: Skeletal Mesh on, Skeleton left empty, Import Materials and Import Textures on, Import Morph Targets on. Leave Convert Scene Unit on.
3. Open the mesh and check three things: the height reads like a person in centimetres, around 150 to 175 depending on your character; the morph target list is not empty, a VRoid face has around fifty; and the body is coloured, not white.

Step 6: Prepare, build, upload

1. Tools → VR Realms Workshop → Avatar, pick your mesh, press Prepare Avatar.
2. Read what it prints. For a VRoid rig you should see the hips found as J_Bip_C_Hips, 21 of 21 chains added, hand IK on 2 arms, a height match line, and a list of skirt, hair, ear and tail chains being given physics.
3. If it asks you to tick Used with Morph Targets on a material, open that material, tick it under Details → Usage, and save. Without it the face goes grey in the packaged game while everything else looks fine.
4. VRoid hair uses transparency. If it renders as solid slabs, set the hair materials to Masked.
5. Fill in the title, tick Anime and Blend Shapes as style tags, then Build → Upload.

What to expect in game

• Your size. The avatar is scaled so its eyes sit at your eyes, the same way you would expect from other VR avatar systems. A small character becomes your height; a tall one shrinks to it.
• Your hands. Hands follow your controllers. If the avatar has shorter arms than you, the arm stretches the rest of the way rather than stopping short.
• Movement. Skirt, hair, ears and tail swing on their own. You can retune any of it; see Physics and jiggle.
• Shading. The soft toon look from VRoid does not survive FBX. Expect flatter, slightly shinier shading. Colours and textures are unchanged.
• Face. The imported shapes are picked up for talking and blinking; see Face shapes.

If something looks wrong

Stuck on something not on the list? Bring the log to #workshop-support. Sending a log shows where it lives.