PDA

View Full Version : Attaching objects to a deforming character



dsol
01-13-2016, 10:29 AM
Hello friendly LW community :)

I'm currently doing my first job that needs an animated character (for a short film) using bones. I sculpted the model in Zbrush and I managed to rig it using Genoma 2, which has sort-of worked (might need remodelling in a T-pose to work properly). However the big issue I'm trying to solve right now is adding objects attached to this character. It's a monster-creature thing, and it's got a clump of splines on its back and some teeth added (in separate layers). These objects are parented to the main character (with the rig), but they don't remain attached to the object surface when it deforms. I could sort-of solve it by moving the spine and teeth objects into the same layer as the boy, but I suspect that the bones will make them stretch and deform, when all I want is for them to "stick" onto the surface of the parent object.

Here's screengrabs showing the before (posing) and after so you can see the issue.

131870131871

I think I've read before you can do stuff like this with FX metalink, but when I tried that it didn't seem to work. Has anyone got any ideas about how to do this? Ideally with a solution that doesn't require baking everything ;)

Big thanks

Dan

ernpchan
01-13-2016, 10:45 AM
You could add hold bones for each thing that needs to attach to the character or use weight maps.

dsol
01-13-2016, 10:59 AM
Thanks - Weight maps are a good call. Further down the line, I'd like to add some hanging robes from the character, make a more visually interesting silhouette (the character is only seen as a shadow). Would that use ClothFX or can you use Bullet soft bodies with Deforming characters?

ernpchan
01-13-2016, 11:05 AM
Would that use ClothFX or can you use Bullet soft bodies with Deforming characters?

I believe the answer is yes to both.

pinkmouse
01-13-2016, 02:17 PM
Dan, you can also attach things with DPkit. Hmm, that might be my next tutorial sorted. :)

Dodgy
01-13-2016, 07:36 PM
For the spines, you can use FX_Hardlink, so they don't deform. They'll be 'attached' to the closest polygon (you can edit this in the Hardlink controls) You'll need to add clothFX or SoftFX to the deforming character for Hardlink to read the motion.

speismonqui
01-13-2016, 07:52 PM
Not sure if this is what Dodgy is talking about... anyway, maybe this can help?


https://www.youtube.com/watch?v=E2gVyyMT8W4

Dodgy
01-14-2016, 12:16 AM
Hardlink is like metalink, but each part is treated like a hard object, whereas metalink interpolates the deformation, like a lattice.

probiner
01-14-2016, 05:18 AM
Hi Dan.
Suggestion. Just use a polygon tag as a place holder for an instance of the spikes as they look similar. This way you only have to manage some small polygons which offer faster calculations or painting, and you can meddle with the spkies size procedurally. Cheers :)

Greenlaw
01-15-2016, 05:57 PM
I'm with with ernpchan. It looks like you just need hold bones and proper weight mapping.

Alternatively, you can add small bones to the rig for the base of each spike and just parent a spike object to each spike bone. That's probably even simpler. (Edit: maybe not...not sure how that will deform with the back of the creature. Might be worth a try though since it's a pretty straightforward idea.)

IMO, yes, you can metalink the spikes but that seems like a roundabout way to do something that should be done directly in the rig.

G.

vector
01-15-2016, 10:48 PM
Not sure if it could help you but I link it anyway. I create a point info node tutorial time ago to explain how to attach an object to a point https://www.youtube.com/watch?v=FXQX7X-UUes

I used it in this add https://youtu.be/MqbgDSY4YEk where the cd box is animated using bones and cd's as objects. When the discs get into the box they have to remain there following the bones animation when closing the box, so I parented them to each null which at the same time were parented to their respective vertices of the box using the point info node of DPKit.

What I had to do later is baking the animation of the nulls with mentalfish motion baker when the animation was right. It's important to know the point info node needs refreshing to see actual results like the motion blur trick Dennis Pontonnier said to me in this forum.

dsol
01-16-2016, 05:41 AM
Thanks guys - this has been really helpful!

Dodgy
01-17-2016, 06:24 PM
Alternatively, you can add small bones to the rig for the base of each spike and just parent a spike object to each spike bone. That's probably even simpler. (Edit: maybe not...not sure how that will deform with the back of the creature. Might be worth a try though since it's a pretty straightforward idea.)
G.

That's why I'm not keen on that idea, you need unnecessary bones which might screw up deformation, and might slide over the skin (because points are influenced by more than one bone, while a child bone only has one parent). Hardlink should keep the spikes parented to the same polys and keep the shape of the spikes.

probiner
01-17-2016, 10:56 PM
Yup and if you just link a polygon tag like mentioned and place an instance, probably faster calcs.
Cheers