Controlling how mesh deforms

Hi all,

I’m a newbie to rigging and i’ve built a rugby player (based on BlueZoo’s BBC rugby idents) to learn with. The low poly res is an intentional part of the design. the problem I’m having; when i raise the thighs, the shorts deform very messily and faces begin to intersect each other (i’m guessing that’s a big ‘no-no’ when it comes to animating???) How do i determine how i get the mesh deforms. Having had a brief root around online, i’m guessing that Shape keys is the way to approach this!?? But any direction and help would be gratefully received.

Apologies if there’s an existing post covering this subject. I did have a quick search! If there is please direct me.

Many thanks in advance
Rugby Giant rigged5.blend (807 KB)

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Hi Chamine and welcome to the forum!

Kudos to you for writing a good first post! You’ve included pictures and the .blend file, all of which are usually needed when seeking help, so your off to a good start here.

I looked at your file and normally I would say your topology needs work, but given the style of the character, there not much room for topology improvements. Some work could be done in this area. A few loop cuts here and there would be helpful.

Second thing I looked at was your weight painting, lemme guess, was it auto weighting? Going to need some work in this area, so if you don’t know how to weight paint, you need to learn and fix the problems you have. There is no noticeable weight in the problem area assigned to the hip bone. The neck also needs work, weight for that bone is mostly on the back of the character, with very little weight on the front of the neck area. Tilt the head & neck backwards to see what I mean.

Normally, I say 90% deformation problems can be cured via topology & weight painting. Good topology and weight painting will only get you half way to a good character with this style. To me, this is like a high poly minecraft style character, and those need shape keys to look good. So you’ll need to work with them, but it’s best if you fix the problems you have first.

Take a crash course in weight painting. Youtube or what ever. Fix those problems I mentioned, and I show you the shape keys setups.

Good luck,
Randy

Rugby Giant rigged6.blend (779 KB)

Hey Randy,

Thanks so much for your reply, Very much appreciated.

I am familiar, if not well practiced, with weight painting. The rig does indeed use auto weights and i had edited them a small amount. I’ve played around some more, as you directed - please take a look at the results and see if that’s as far as i can take the deformation using weights. I did assign parts of the shorts/pelvis region to the hip bone. However, when i went back into weight paint mode they had, repeatedly, been removed (entire figure was magenta colour)!??? I understand that you can assign a vert to more than one bone and the deformation will average between them, so i don’t understand this removal behaviour!?

I’ve actually built this model on a series of TV idents. I intend to pose the character and take a print as a gift for my step dad, who’s is very fond of the idents. For this reason i’m reluctant to change the topology much, as I’ve designed it as close as to the original dents. You can view the idents via the link below.


Anyway, thanks again for your time and advice.

Cheers
Si Chamine

If you are just statically posing the model and making renders, then the job is easy. Pose the character, select the mesh, and find the armature modifier for the mesh. Enable all the buttons at the top of the modifier, 3 buttons, once they are enabled a 4th one appears, enable it. Now you can pose the character, select the mesh and enter edit mode and you’re free to move verts around. So move the verts around until the mesh looks right and render.

Like so:

A karate kid style pose, and I edited the verts.

Creating shape keys is the same process but they are meant to be reusable. Useful for animation, but not worth the time for a simple static pose.

Cool looking character. If I had the time, I would rig it up and play with it…

Randy

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Thanks Randy,

I think i’ve been a bit misleading. The purpose of this character was 2 fold. I am going to take a 3D print of the character but i also built him with the intent of learning rigging, so if ur able to direct me further re. shape keys, (or recommend a good online tutorial) would be much appreciated.

Also, i’ve done more weight painting. I had been assigning vets manually in edit mode, but realised its so much more easier with wght paint brsh. New version attached.
many thanks

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Rugby Giant rigged6.blend (706 KB)

Yea, I can help direct you on rigging, weight painting, shape keys, etc… I haven’t been that active with blender, so I need to stay in touch with my skills. So let’s talk weight painting…

As you figured out, you want to be using the weight painting tools to do this. When weight painting, it’s possible to weight a vert 100% to one bone and 100% to another bone, or many other bones. If a vert is weighted 100% to two bones, the vert is actually weighted 50% to each bone. If a vert is weighted 100% to 3 bones, it’s actually weighted 33% to each bone. All bone weights add up to 100%, or 1 as blender displays this in a decimal value. So what you are seeing on the screen may not be the actual weight, see a red vert for two bones, it’s not 100% weighted to those 2 bones. So the next time you go into weight paint mode, look under weight tools for Normalize All and click it. This recalculates the weights of the entire mesh so they are the actual weight. Under the brush options, there is a Auto_Normalize checkbox, enable that and blender keeps your weights normalized while painting. Now as you ad weight to a vert for one bone, weight is subtracted from other bones and the result is seen on screen.

Personally, I like to weight paint on a solid mesh with a wire display, like so:

This allows me to see where the verts are, every line intersection. That’s the last file you posted, and notice there are no verts assigned to the hip bone, the one currently selected. Look at how the faces on the butt are stretched. You need to reduce that stretch and it will look better. So after normalizing all and enabling auto-normalize, I went to work:

And the deformation looks better. It still may need a shape key to get the desired look, but it’s best to fix what you can now, before moving on to more complex fixes.

So where did you get that rig? From video tutes, parts of a rigify rig? Did you build it yourself?

Randy

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