Rigging problem-Skin Weights not having full effect

Stu2Prof · Mar 2016

Hi guys

I am currently trying to rig a robot in Maya but am having problems with the skin weights. I am currently working on his arm and although I have sections of the arm painted in complete white (Fully effected) the movement of the rig seems to be only having 60% of the effect when I rotate/move it. Im not sure where Im going wrong on this but I have a link to some screenshots below to help explain. Thanks for any help you can offer me and I hope you're having a nice day.

http://imgur.com/a/TeSTJ

Bartalon · Mar 2016

I'm seeing some gradients in your weighted areas where it is not 100% white. Even in areas that appear 100% white this may not be the case. Try checking the Color Ramp checkbox and using the colors as a better indicator of skin weighting. You may find that some areas are yellow, green, or blue--any of which are less than 50% influence. Vertices that are influenced by multiple joints will not be white.

You can also use the Component Editor window (Window > General Editors) to get a deeper, more precise view of which bones are influencing certain vertices. In the Component Editor, go to the Smooth Skins tab. With Options > Hide Zero Columns checked, it will only display the joints that have influence over the vertices you have selected, and you can manually punch in values to zero out any bad influences.

battlecow · Mar 2016

you are working with replace. YA SHOULDNT!
Work with ADD and go from master to slave.
Bind the arm completely to the shoulder then work your way down.

Stu2Prof · Mar 2016

@Bartalon Thanks for the color and component tips. The color ramp helped me identify some areas that needed to be touched up. Some red areas among mostly white. However the problem has not disappeared

My Maya's behaviour seems to indicate that a value of above 80% is white and 70% is red which seems a little bit different from what you described. I am also noticing some problems with my viewport updating my paint weight edits(I need to cycle between viewport 2.0 and default viewport for changes to load) so there may be an issue with my software. I have a link here to my edits and what I am seeing including the component editor info.

@BATTLECOW The reason I am using Replace is so my 0 value numbers take effect. When I am painting in Add mode the zero values dont effect anything. Can you explain why you recommend only using Add? I have bound the arm completely to the shoulder and am decreasing the influence as I go which is partly why I am confused things are not working for me.

battlecow · Mar 2016

Hum How to explain this ...
Let's take the arm exemple again. After totally binding it to the shoulder you then go to the elbow and completely bind the arm from the elbow and down to the fingertips, you decrease the shoulder's influence by adding some on the elbow. You work your weight down and balance the weight between the two joints by checking with an animation and smoothing or adding where needed. Really small increment settings (intesity set a 0.03) help you get the deformation you want.
When you replace influence with maya's default 4 influence per vertex, the software balances it out adding other influences and totally messing with your work, you might have noticed it each time you switch joints.
Hai Phan has a tutorial about this, I believe it's not free but it's really cheap, I highly recommend it. (EDIT: I tried to find it and link it to you but I don't seem to be able to)

NGSKINTOLLS migh also be a lot of help, it replaces Maya's weight painting tool and is just better, and free

Stu2Prof · Mar 2016

@battlecow Thanks for the response. Just need a little more detail to help me understand. So far I have everything influenced by the shoulder and am decreasing the areas of influence as I go down the hierarchy of joints towards the fingertips which seems to be what you are suggesting in your first sentence.
"you decrease the shoulder's influence by adding some on the elbow" - adding some of what?
"When you replace influence with maya's default 4 influence per vertex, the software balances it out adding other influences" - I'm not sure what you mean by "replace influence with Maya's default"

NGSkintolls looks great by the way.

Thanks for your help so far.

battlecow · Mar 2016

It is so hard to translate without images lol.
Every vertex has to be 100% painted/influenced at all times , if you remove/replace some influence most of the times your vertex will not be a 100% painted and Maya will try to balance it by adding influences from other joints.

The way you remove influence on the shoulder is by addind some influence (Adding paint) on the elbow

I suggest setting max influences (in the drop down menu of the soft bind option) to 2 or even 1 since you have a very low poly mesh.

Also just a tip : combining or separating already skinned meshes fucks everything up

CheeseOnToast · Mar 2016

Would you mind showing your skin bind settings? It should have stored the ones you used last, so just screenshotting the smooth skin dialogue box should be enough. I noticed that in your weight painting settings, normalize is set to "off". You really want this set on, and set to "interactive" which will make sure that the influences on any particular vertex will always add up to 1.

A lot of skinning issues can occur right at the start by choosing the wrong skin bind settings. Unfortunately, the defaults are not an ideal choice in most cases.

Also, +1 for NGskintools. Amazing bit of kit. Grab the Dora Skin Weights script at some point too. It allows you to save weights to another file and transfer them easily to other meshes via vertex order, world position or uv position.

Rigging problem-Skin Weights not having full effect

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