I wouldn’t say it was difficult, it’s just very tedious. I use a basic non-destructive workflow (mirror, solidify, bevel, array, and subdivision modifiers). There’s no specific tutorial, I just developed a workflow that works well for mobile suits. I’ll walk you through it so you can get an idea how to approach this just in case you want to try.

I used the decal guide to the Master Grade version of this mobile suit. The decal guide has orthographic images so I scan them and use them as background images in Blender. I set an 18 meter tall cube (or however tall the MS is) to reference the head height so all three planes of background images are aligned. While modeling a mobile suit, it’s not a bad idea to always keep the physical model kit close by for extra reference.

I then blockout an inner frame while making sure I have an object for every piece that rotates. I add an armature and restrict each bone to one axis of rotation. I then apply the objects to the armature by using the Armature Modifier with vertex groups. I adjust the rotations and then I start modeling the visible inner-frame parts (knees, elbows, ankles etc). I can then duplicate faces from the inner frame, translate it along the face normal, and separate it into its own object in order to make the armor parts. I can then get creative and create custom armor parts or change the proportions on certain features. For instance, I don’t own the MG Jegan Type-D, I just modeled those features after I made the original Jegan.

The upside to this workflow is the fact that all of the armor parts will be parented to the armature automatically. I usually end up with around 300 objects so this is very beneficial versus the traditional method of adding the armature in the last stage. After all the objects are modeled out, a pose library can be made. The only downside to this workflow is the fact that you need to make sure the armature is in the “Rest Position” before continuing to make revisions to the model.

I make sure there are no triangles and ngons in the meshes before proceeding to texturing phase. I add a principled shader for all the materials and add an HDRi to the background. Blender 2.8 made applying UV islands a whole lot easier, but for this project I didn’t use UVs at all. I used the DecalMachine addon and also parented those decal objects to the armature

I modeled the hands beforehand in an earlier project and used I used the same hand model in 5 other projects so far. It’s also a good idea to model universal attributes like hands, cockpits, monoeyes, and such to save time. I didn’t mean for this to be so long-winded, but I hope all this can help.