How to animate "swelling", growing from thin air, shooting?


Im very new to blender but have been trying to develop my own game. I model my objects in zbrush and then take it into blender. So far, ive learned how to rig my characters and have them walk and run and jump, but there are some special skills i want to happen in the game and i have no idea how to do or how to find tutorials on them. Ill import these animations into unity!

Essentially, i have different characters that have unique looks:

  1. One, will running, will have the bottom of their foot stick to the ground and rip off, and while in the air another will grow back in its place, and again and again
  2. One has no arms but tentacles instead, i want the tentacles to form together and “meld” into an arm during an attack
  3. one has no legs but floats, i want legs to grow out of the air and appear during a jump
  4. one can suck up water , so i want its arms to “pulse” cartoon-style with the water swelling a lump in its arm and the lump moving up, and then can also shoot a water ball.

ive tried to look for weeks for tutorials that teach this on youtube (its how i learned to rig and animate a walk cycle, but thats the extent of my knowledge) and i have no idea how to find it or what to do, or if its even possible in blender


I can’t say I’m an expert on this, since I’m barely into animating myself, but here’s my little bit.

Ripping the feet off and melding the arms seem very tricky to do in 3D. It is doable, though.

Ripping Feet:
You’ll want the feet to be a separate mesh, and figure out the growing animation on that independently. In order to get the foot to match seamlessly with the leg while “attached,” you can use the Data Transfer Modifier. To get the tearing itself looking attractive, I don’t have any experience in that, so you’ll want to do some research on that.

Melding Arms:
Your best bet here also lies in a separate arm mesh. Create and animate the arm in object that doesn’t show up in the render.
The tentacles will probably use a combination of the Shrinkwrap modifier (or shapekeys) and the Data Transfer modifier, activated in that order.

I don’t know how you want the leg to grow, but it also should use the Data Transfer modifier to become seamless with the torso if that area is visible.

As for the pulsing arms, you could do this in any number of ways, some of which are more flexible than others.
If the arms are pretty simple geometry, you could use the shrinkwrap modifier with Project, set it to only follow in the positive direction, and then animate separate meshes constrained to the arm bones to represent the water.

Another method (if you want to preserve non normal mapped detail on the arm during the pulse) uses a much more complex arm deform rig. If you use maybe three or four bones for each arm segment, you could scale them on their X and Z axes to create the pulse.

These are all really advanced animation techniques, and they all involve modifying or creating a custom rig for the various body parts. I’d recommend getting really comfortable with the actions on the non-modified rigs first. You know, you want to make sure the action feels good at a base level, before getting into all the fancy stuff.

Alternative ideas…


Could you not just have a ripped off foot model that unhides at the exact spot when the foot lands and scale the rigged foot on that same frame instantly to 0.1 and animate back to 1.0 in the stride? Do the unhiding of the ripped foot model in Unity not in Blender so it leaves a trail of ripped off feet instances that are not bound to your animation.


For the arm, create an arm first then modify it to a tentacle and use a shapekey for the morph.


For the legs, hide them inside the body, when the character jumps animate them popping out in the air (or use stretchy bones if Unity supports it). Or just use a transparent shader in Unity that animates the legs material visibility when jumping. In fact you could probably animate all that in Unity once the rig is done.

Water sucking

For the sucking up water arm animation, use a Cast Modifier on the arm, set to sphere and just animate a control object moving up the arm so the spherical inflation animates along the arm, this will give the effect of a 2 inch ball bulging down a 1 inch pipe. To fire water balls it is the reverse of this effect. Bake these keys for use as a Unity animation clip and isolate the arm in Unity mecanim so the rest of the rig is unaffected.