Module 09 · Export to Engine — BlueCat 3D AI × 3D character pipeline

/ 01 · What this step does

Finish line: into the engine, checked, shipped

Picking up from Module 08: you have a rigged, animated character — now you move it into a game engine and get it running.

The tech here is easy, but it's where the classic disasters strike: you drag it in and — textures gone, scale blown up to giant size, character face-planted into the floor. None of that means your model is broken; it means the data conventions of your DCC software and the engine don't line up. This step is all about making that handoff clean.

/ 02 · Pick a format

GLB or FBX? This decides whether your materials survive

GLB / glTF

Carries metallic-roughness PBR natively — base color, metallic, roughness, normal all in one pass, textures embedded in a single file. Unity/UE/Godot/Web all eat it. Try this first for characters.

材质最稳 · PBR 材质干净过去

FBX

The engine standard (best skeletal-animation compatibility, especially), but it predates PBR — metallic/roughness/normal often get dropped, and usually only base color transfers reliably, so you reconnect textures by hand.

骨骼最稳 · 骨骼动画首选 · 材质手动接

/ 03 · Step by step

From export to standing firm in the engine

9.1

Export settings

Apply all transforms (reset position/rotation/scale), then export.
Check the axes: Blender is Z-up, most engines are Y-up — set Forward/Up correctly on export so you don't get a face-plant.
Tick embed textures (GLB does this by default); FBX carries a separate textures folder.
Skeletal animation: confirm the export includes the Armature + animation tracks.

9.2

Import into the engine kill the recompute

Drag into Unity 6 (source file stays in Assets, the engine converts to an internal format) or UE5's Content.
Turn off Recompute Normals / Recompute Tangents — so the normals you baked in Module 06 don't get overwritten by the engine.
Remember to import the textures folder along with it.

9.3

Fix scale and orientation

Unit mismatch: Unity 1 unit = 1 meter; UE 1 unit = 1 centimeter. If the scale is off, adjust the Scale Factor / import scale.
Check against reference: a humanoid is roughly 1.8 m tall — don't let it become a giant or an ant.
Wrong orientation (face-planting, lying down) = axes didn't line up; go back to 9.1 and reset the export axes.

9.4

Hook up materials color space

Connect the PBR textures from step 07 to the engine's metallic-roughness material (GLB usually wires this up automatically).
Get the color space right: base color / emissive are sRGB; normal / roughness / metallic / AO are linear (non-color). Swap them and the result goes gray and muddy.
Watch for channel-packing differences: Unity and UE pack metallic/AO/roughness differently, so repack when needed.

9.5

Hook up skeleton and animation

Import as a Skeletal Mesh (UE) / set up a Humanoid Avatar (Unity).
The effort you spent in Module 08 standardizing bone names pays off here: animations retarget straight away, no redo.
Play an animation through once and confirm the deformation matches what you had before export.

9.6

LODs and collision depends on use

For a game: generate LODs (low-poly versions at distance to save performance) and add collision as needed.
For a pure portfolio showcase: you can skip this and put your energy into lighting and rendering.

9.7

Final sign-off + render out

Drop it into a lit scene and orbit around to check the materials read right under real lighting.
Play the animation + pull back to confirm the deformation is clean and the silhouette holds up.
For the portfolio: record a turntable + idle/walk animations and grab a few still frames. That's your finished piece.

/ 04 · Engine cheat sheet

Unity 6 vs UE5 — the key differences

Two engines · checklist

Units: Unity 1 unit = 1m · UE 1 unit = 1cm

Preferred format: both eat FBX/GLB · GLB first for character materials

Import normals: turn off Recompute Normals/Tangents in both

Materials: both use metallic-roughness PBR · check color space

Animation retargeting: Unity Humanoid Avatar · UE IK Rig Retarget

/ 05 · Core discipline

Three iron rules

① Keep materials alive — favor GLB. FBX dropping PBR is the number-one disaster; try GLB first for any textured character.

② Turn off normal recompute. Otherwise the engine overwrites the normals you worked so hard to bake, and it's all for nothing.

③ Keep color spaces straight. Base color / emissive are sRGB, everything else is linear — swap them and the whole character goes gray.

/ 06 · Common wipeouts

The three classic import disasters

Textures all gone → FBX dropped the PBR; switch to GLB or reconnect textures by hand.

Scale is a giant / an ant → unit mismatch; adjust the Scale Factor.

Character face-planting / lying down → axes didn't line up; reset export Forward/Up.

Normals look blue, surface is weird → recompute wasn't turned off / tangent space mismatch (go back to 06 and check).

Whole character goes gray and muddy → color space swapped (normal/roughness wrongly set to sRGB).

Animation won't retarget → bone names aren't standardized (go back to 08 and rename).

Performance stutters → no LODs, still running full poly count at distance.

/ 07 · This step's deliverable

Tick these off and you've graduated

Character in-engine: scale right, orientation right~1.8m, standing on the ground, facing front

Materials correct under real lightingmetal reflects, cloth is matte, no gray-out

Animation plays and retargetsdeformation matches pre-export

A portfolio showcase clipturntable + idle/walk + stills

Full project files archived→ 09_engine, all nine steps kept on record

/ 08 · Final self-check

🐾 Three questions — pass all and you've made it

Orbit around in a lit scene — are materials, scale, and orientation all right?
Play the animation — is the deformation clean and the silhouette solid?
Can you record a turntable + animation and drop it into your portfolio?

▸ All three pass → congrats, your character went from concept to engine. 🐾

/ Fin · The whole pipeline in review

Nine steps, one line — you walked the whole thing

01 Concept design · AI generates multi-view reference · ⚡ AI

02 3D model generation · image to base mesh · ⚡ AI

03 Sculpting · clean-up, reshaping, locking the silhouette · 🐾 guided

04 Retopology & optimization · clean low-poly + edge loops · 🐾 guided

05 UV unwrapping · flatten, hide seams, unify density · ◐ hands-on

06 Texture baking · high-poly detail → normal and other maps · ◐ hands-on

07 Painting + materials · AI base color + hand-tuned PBR · ◐ hands-on

08 Rigging + animation · auto-rig + weight fixes · 🐾 guided

09 Export to engine · into Unity / UE5, closing the loop · ⚡ AI

From a single sketch to an engine-ready character

The slow grind you handed to AI; the craft you practiced with your own hands. This production line now lives in you — it won't age out with any single tool, because what you understand is the logic of the whole line.

Next up: take this workflow and make your own second character, then a third. Faster each time, and more and more like you. 🐾