Learning Blender 3D – Animation and Export Problems

Blender Day 2. I got onto doing the last of the needed assets quite easily. What took half the day before was down to a solid hour. It was all about syntax and the tools now. I’ve been around game artists and assets as a dev long enough to know what needed to be done. I’ve studied form and shapes as a hobby in art.

With stuff for work done, I thought about what I really wanted to model for myself. And then it dawned on me – ZGMF-X09A Justice Gundam’s Fatum-00 lifter unit. I love this design. The jet-like backpack, and how it attached to the mobile suit. I wanted one. The most recent incarnation from the Master Grade kit was the sleekest one yet with some great edge designs. I still prefer it over the Infinite Justice’s unit, minus the sword extension and beam blade wings. I gathered reference images of the kit from different angles, then started drawing the plane blueprints. The initial shapes were roughed out in Blender on the first night.

Day 3. The shapes on the redesign of the thrusters are so iconic and I really wanted to capture them. Every time I looked back at it I found something to tweak just to get it right. With a few more hours of experience I was getting the hang of things. Enough to find my own flow and style to put into the low poly look. The wings, fins, and their caps were a challenge again. I learned more tricks like better Vertex/Edge/Face alignment, more Knife cuts. Now I was molding all the surfaces to my liking. While exploding the tris and face counts.

Day 4. I finished the false cockpits by the end of half the day. It looked quite sharp and really finished the entire unit off. It was satisfying to have it finally done. Then I wanted to try something else – the folding gimmick to set it into idle mode.

I found out that there are a lot of animation options in Blender. From basic keyframes to rigging with armatures. I went through a lot of trial and error to see what works. Multiple copies and attempts were made for the rest of the day. Keyframes and Actions with multiple Objects was fast inside Blender, but it didn’t work on import in Unity. The Actions were multiplied by each object and ended up a mess. I didn’t even bother to test if it worked as there were even Pivot/Origin errors.

Next I tested Armatures. I found a quick video tutorial to study. It requires an extra step to Rig all the Bones and parent them properly to each Object. After that is the same keyframing or Posing. The Actions exported to Unity neatly named and sorted. But the armature’s effects were wrong. Specifically regarding Mirrored meshes. I hit a huge roadblock with the workflow.

Mirroring, as I found in the first day of learning 3D modeling, makes life a lot easier. It allows you to sculpt only half of the entire model (if it’s symmetrical). It saves a lot of time in UV unwrapping because the model duplicates the pixels on the opposite faces. Armature Bones could be parented to half the objects. But this is all only inside Blender. Exporting to Unity automatically applies the Mirror modifier. It needs to because this is where it creates the data.

Applying the Mirror modifier inside Blender is irreversible, it’s a hard commit. I would call it a destructive workflow. If I want to create the animations inside Blender only to be exported I would need to apply it. Remodeling, re-texturing, rigging would literally take twice the time or more. I think it’s not worth it.

There might be a solution to maintain the Mirroring modifier and keep the Object hierarchy intact. And that is NOT animating in Blender. Just animate with Unity’s engine. For me, having a mutable model file that I could revisit is worth a lot more for its flexible workflow. The export will be clean and sorted too. Maybe that’s just my programmer’s perspective talking. Having a permanent change that affects the majority of the process for just simple animations is a deal breaker.

Day 5. I tried a more minimal solution to the animation timeline in blender. One Take with all the Keyframes, then slicing them up during the Unity import. It worked well. I could key in Blender but the mirroring problem still existed. When it was applied on export, the meshes only animated with respect to one side’s pivot points and behaved as one big object.

The last trick up my sleeve – export only half the model without modifiers. Combined with the simple animation timeline the import looked clean. I made the Mechanim easily and hooked it up to the GameObject. It would take extra scripting to sync the two halves together. Or again, scrap the keyframes from blender and duplicate the meshes to make new keys inside Unity itself.

Exported Mirror modifier problems in Unity
Half the model, half the problems

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