Shapeshifter game character using Morph Targets?

Hello everyone! I’d like to apologise in advance, because I’m going to be asking for support on a very advanced topic while having very little prior in-engine experience. I do however have fairly extensive experience with Autodesk Maya, and I’m well versed in game modeling techniques and practices, as well as the full workflow for creating game characters from start to finish (exlcuding engine implementation of course…). NOW, on to the topic at hand:

I’m currently working as a 3D artist on a game project for school. We just began working on it this week, and are in the process of laying out our large scale planning, core goals, and strech goals for the project as a whole. We aim to have 7-8 weeks of full-scale production time at our disposal. Our main visual inspiration are Firewatch for the overall visual aesthetic, and Journey for the character design. Our core design philosophy revolves around defying player expectations in terms of both narrative and mechanics: minimal UI, no dialogue-based NPC interactions, etc.

One of the core features we want implemented is the ability to seamlessly shapeshift from a humanoid into two different forms: one flying form and one swimming form. We’d love for this transformation to feel extremely organic, and thus we’d like to avoid the classic “puff of smoke” route were we simply switch out the character models and hide the transformation sequence with some kind of particle effect. Our animator and I have been spitballing about how we could achieve this goal, and while I know from some very basic art tests that it’s possible to import basic Blendshapes from Maya, we’re kind of stumped as to how to proceed from here.

A couple questions of the top of my head that may or may not be relevant:

  • Is it possible to blend between skinning weights in the same way you can blend between meshes using Morph Targets?

  • Is it possible to blend between UV sets for a character model? If not, should we perhaps take this in consideration for our character design, and make sure to be extra careful when laying out our UV splits? Make sure we limit our colour palette to basic color fills for each UV island, or at the most basic gradients? The reasoning behind this being that while the texture may technically be horribly stretched after deformation, it wouldn’t actually be visibly noticable in-game.

  • Is it possible to seamlessly switch back and forth between character rigs? If so, you should be able to simply create unique rigs for each transformation and switch between them during transformation.

Here’s the concept trailer our Art Director and a couple other team members put together: It’s also a good representation of our target resolution for our 3D art: we’re aiming for a fairly low-poly aesthetic.

Hope you guys can help out, any feedback at all is greatly appreciated :slight_smile:

Sure it can be done and if you tell the material to “uses morph” the UV mapping should not be a problem but you should be able to set up different UV mapping channels.

You can set the character up to use a full body morph but since UE4 does not support progressive morphing you will have to set it up using a series of progressive targets to avoid the pop from point A to point B effect. Since morphing is additive the rigging should not be to much of a problem with a little planning.

I suggest you create a custom animated skeletal mesh for the transformations from and to the different shape.
That way you can have the character rig in each of his shapes be solid and clean without any heavy blendShapes and material tweaks and additional tweaker joints and whatnot.
So what you do is have a skeletal mesh on the same base skeleotn with one animation (the shape shift process) and all required moprhs, helper joints, shader adds. That mesh then is visible during transformation, and should the visibility should seamlessly transition between the regular game mesh and the transformation mesh once the animation is finishing.

GoblinCrusher94 any luck with this? I have a similar “morph” action I need and this was the closest thing I could find. Also, I may try the idea of hiding the transformations behind a particle effect. Does anyone know where I might find a tutorial of something like this? Thanks guys!