Need workflow suggestions

Help
1

Hey
I am animating a scene which includes Trex vs Raptor
At one point the Trex bites the raptor and moves the raptor in air and latre throw him down on the floor.
So, I want to simulate the Raptor using ragdoll while he is in the mouth and getting thrown down.
I have already made the Ragdoll rig for the raptor.
I am super new to Ragdoll so wanted some suggestions what would be the best way to achieve this.
Thanks in advance

2

Hi @animator_mrinal, welcome to the forums! :partying_face:

Are you able to post the animation you have so far? It would help to determine the best way to tackle any simulation with Ragdoll.

3

Hey. Thanks for the reply. I have attached the playblast of the animation above. Right now the Raptor is roughly constrained to the Head controller of Trex.

4

Perfect, this is a solid use of Ragdoll.

Here’s how I would approach it.

  1. Setup the raptor with Markers. See e.g. here for example.
  2. The T-rex won’t need any physics :+1:
  3. Leave the main Raptor rdGroup as Behaviour = Animated until he gets picked up, then animate to Simulated
  4. Leave the Raptor hip or torso Marker as Animated, that way it’ll still follow the animated Raptor
  5. Once he lets go, animate the hip or torso to Behaviour = Use Group such that he falls naturally to the ground

For step (1), feel free to post the Raptor along with a “drop test”, i.e. just the Raptor falling from A-pose/T-pose to the ground. That’ll help get some idea of shape sizes and limits that we can feedback on.

Whilst in the air, you can tune primarily the Rotate Stiffness of the rdGroup of the Raptor to make him less or more stiff, I’d imagine you’d still want him somewhat animated to maybe kick his legs or try and bite the T-rex as he’s up there. The more stiffness you give him, the more active he’ll be able to be. Here’s an example of that from the Blender version which is also applicable to Maya.

Looking forward to seeing the progress!

5

Thank you so much for the detailed reply. I quickly went through your method and was able to achieve this result.
I definitely need to tweak the properties to get organic movements but I am happy to know how this works now. Attaching the result for your reference.

6

Yes! That does indeed work great; some ideas to tweak.

  1. More friction on the ground. That way he’ll roll more, rather than slide.
  2. More animation on the Raptor, e.g. neck, he looks very patient :slight_smile:
  3. There is some intersection between Raptor and ground as he’s grabbed; you could either (A) tweak the T-Rex animation or (B) make the T-Rex neck + head dynamic also, such that it also collides with the ground
  4. Maybe even more animation of Raptor after he is released, to make him look wounded and dying, rather than instantly dead

Great job on that Raptor setup, looks fantastic!

7

Hey @alanjfs
Thanks for all the suggestions.
I managed to tweak the animation a bit.
Haven’t worked on the intersection part though.
My main concern right now is to make the Raptor fall more organic/believable.
Currently it bounces and rotates like a toy when he hits the ground.
What properties would you suggest to make it organic and finish in a good pose?
Like at the end it currently feels like a toy single piece.
Attaching latest playblast for your reference.
Thanks again for all the help.

8

Looks awesome!

One of the things that can contribute to a toy-look is the hard contacts and non-deformable behaviour of the Markers and ground. A small plastic toy would behave similarly when thrown against a marble floor, but large fleshy creatures in the real world do a lot of squishing, as does the ground.

In the next release, you’d have soft contacts to help with this. But in the current release, there are at least 2 things you can try.

  1. Translate Motion = Soft
  2. Soft plates on the ground

With soft translate motion on either the entire raptor, or parts of it, you would allow for limbs to squish and stretch. This can help ease the impact onto the ground, making it look (in motion) as though the shapes themselves are the ones squishing.

Although you can’t make the ground soft, you can make the ground dynamic and have the ground try and follow a target ground with some softness, creating the illusion of a soft ground.

It’d then be up to some post-process to restore accurate ground contacts during render, like adding grass or doing an additional cloth-simulation on the ground to match the intersecting parts of your character.

This, in addition to soft translate motion on the limbs:

Now your controllers would have animation on their translate motion, which you may or may not transfer onto your raptor rig. By merely being soft in simulation it will start to behave and feel more soft, even if those translate values aren’t recorded.

Things to tune is the Translate Damping of the raptor, to control the amount of jiggle between limbs, and also damping and density of the ground, to control how deep and how soft the ground should be.

I’d probably also add some detail to the ground; I think the visual of falling and sliding onto a perfectly flat surface also contributes to the toy-feel, as it looks like one big marble floor.

Finally, I’d probably also tune your scene scale; even though it may be at a realistic scale, having things happen faster (larger scene scale) could help make things feel more weighty and less floaty.

9

Thanks for the suggestions I will definitely try this.
Other than this I can notice that after the raptor touches the ground the body works like a single object.
Like All the parts of spine move together as if in FK, same with the Hands and legs they move as a single piece.
Is there a way to break this rotation and make it loose?

10

That is governed by the Rotate Stiffness and Damping of the Raptor. With values at 0, it would instead behave like a metal chain. At very high values, it would behave like a single rigid object.