Skinning a Character in 3ds Max - Part 5 - Hips

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Industry
  • Games
  • Design Visualization
Subject
  • Animation
  • Character
  • 2013
  • Character Animation
  • Workflow
Products
  • 3ds Max
Skill Level
  • Advanced
Duration
10 min

Skinning a Character in 3ds Max - Part 5 - Hips

In this tutorial, you adjust the skinning on the hips and upper thighs areas.


Notes
  • Recorded in: 3ds Max 2013
  • This tutorial is intended for use with 3ds Max version 2013 or higher.
Transcript
00:00:02 --> 00:00:07
It is obvious from the current animation that the hips area needs quite a bit of adjustment.

00:00:07 --> 00:00:12
This includes the thigh joints, buttocks and lower belly areas.

00:00:13 --> 00:00:19
Adjust the timeline to view the scene between frames 360 and 880 to focus on that area.

00:00:19 --> 00:00:24
The thigh joints (along with the shoulder joints) are among the most difficult to skin properly.

00:00:25 --> 00:00:30
Perhaps the term "difficult" is badly chosen here, as the process is the same as you have already learned,

00:00:30 --> 00:00:35
but it does take more time and effort to get this area to work to your liking.

00:00:35 --> 00:00:39
Don't let that scare you as the principles you have already learned still apply.

00:00:40 --> 00:00:46
First you start by blocking out the skinning, by selecting vertices and assigning them to their closest bone,

00:00:46 --> 00:00:51
and then you blend joint vertices to react to two or more bones.

00:00:51 --> 00:00:56
This means selecting one or more skin vertices, select a bone to affect them,

00:00:57 --> 00:01:01
and adjust their weights until it visually makes sense.

00:01:01 --> 00:01:05
With the proxy mesh selected, enter Edit Envelopes mode.

00:01:07 --> 00:01:13
In a side view (such as the left view), use the lasso tool to select vertices around the hips area.

00:01:14 --> 00:01:17
Do not go too low or too high at this point.

00:01:18 --> 00:01:25
In a facing view, add the vertices around the crotch area.

00:01:27 --> 00:01:32
Go around the back and add any vertices that should be part of the selection.

00:01:36 --> 00:01:42
Block out the selected vertices to follow the hips bone 100%

00:01:45 --> 00:01:50
Do not worry about the character's right leg at this time. You'll use Skin Mirror tools in a second.

00:01:51 --> 00:01:55
Obviously the belly area needs some work as well.

00:01:55 --> 00:02:01
Go back to the left view and select the vertices around the lower belly bone.

00:02:03 --> 00:02:11
Select the lower belly bone (or Spine1) and assign it a 100% influence on the selected vertices.

00:02:12 --> 00:02:16
Go up the spine, select the vertices around Spine2.

00:02:16 --> 00:02:21
Select the Spine 2 bone and assign a 100% influence to block out that area.

00:02:22 --> 00:02:24
You'll worry about the torso later.

00:02:24 --> 00:02:28
Now that you've blocked out the work, you can go in and fine-tune the weights.

00:02:29 --> 00:02:32
The concept is the same as what you have already learned.

00:02:32 --> 00:02:38
You need to select a vertex loop, and blend its values between two or more bones.

00:02:39 --> 00:02:42
Adjust your view again to look at the character from the front.

00:02:43 --> 00:02:47
If you haven't done so already, press G to disable the grid.

00:02:47 --> 00:02:54
Check out the left thigh joint around frame 490. It is clear that these skin loops need adjusting.

00:02:57 --> 00:03:01
The process should now be familiar to you. Select a loop, such as this one.

00:03:02 --> 00:03:05
Remember you can use the Shift+2 hotkey you defined earlier.

00:03:06 --> 00:03:12
If a loop is broken as is the case here, then you need to work a little harder to make the proper selection.

00:03:15 --> 00:03:19
Another powerful selection method is the Paint selection tool.

00:03:19 --> 00:03:24
With this tool you can select vertices by "painting" over them, which involves a simple click and drag.

00:03:25 --> 00:03:30
However, if you intend to use that tool, enable the Backface Cull Vertices option.

00:03:30 --> 00:03:36
This way, you're only selecting vertices in the foreground which makes the selection more predictable.

00:03:37 --> 00:03:41
If you don't use backface cull, you'd be selecting background vertices as well.

00:03:42 --> 00:03:48
Be sure to always double check your work as the BackFace Cull option is not always reliable.

00:04:04 --> 00:04:11
Start by assigning these vertices to follow the thigh bone by a factor of 100% if they're not already set this way.

00:04:12 --> 00:04:16
Now you can fine-tune them to also be affected by the hips bone.

00:04:17 --> 00:04:23
Make sure you are around frame 490~492 where the character is doing an extreme split.

00:04:24 --> 00:04:31
With the vertices still selected, select the hip bone and press Shift+1 to activate the vertex weight script.

00:04:32 --> 00:04:35
Click and drag to add a bit of influence from the hip bone.

00:04:36 --> 00:04:40
Don't overdo it just yet, you can always come back and make further adjustments later.

00:04:41 --> 00:04:46
You may decide that the vertices on the selected loop should have different weight values.

00:04:46 --> 00:04:50
Use the Alt key to remove the top vertices from the selection.

00:04:50 --> 00:04:55
Use the weight script again (Shift+1) to adjust the weighting a bit more.

00:04:55 --> 00:05:01
Keep on adding or removing vertices and adjusting their weight to get a result that you like.

00:05:05 --> 00:05:11
Move to the next thigh loop, this one should be easy to select using the Shift+2 hotkey.

00:05:11 --> 00:05:17
Again, work the weights of the vertices on that loop to be a little affected by the hips bone.

00:05:18 --> 00:05:23
As before, you may need to work the weights on individual vertices on that loop.

00:05:25 --> 00:05:28
Adjust the next loop in line moving down the thigh.

00:05:29 --> 00:05:31
This one needs very little weight adjustment.

00:05:31 --> 00:05:36
Keep in mind you will almost certainly be coming back to adjusting these vertices at some point.

00:05:36 --> 00:05:40
In other words, do not worry about getting it right the first time.

00:05:41 --> 00:05:46
Alternate between the Paint Selection tool in Backface Cull mode and the lasso tool.

00:05:46 --> 00:05:49
Select vertices and adjust their weights.

00:05:50 --> 00:05:54
Keep an eye on how the mesh is deforming and adjust the weights accordingly.

00:05:54 --> 00:06:01
This means you select one or more vertices, select a bone of influence, and adjust the vertex weights accordingly.

00:06:02 --> 00:06:10
Keep on selecting vertices and adjusting their weight until the deformation seems to behave properly.

00:06:13 --> 00:06:17
Do not adjust vertices on the character's middle line yet.

00:06:25 --> 00:06:32
This will take you some time but it is redundant work, so we'll skip the movie ahead to limit its length.

00:07:00 --> 00:07:06
Once you are satisfied with the deformation, you can mirror the skin data to the other leg.

00:07:08 --> 00:07:14
Enter Mirror Mode and use the Paste Blue to Green Verts function.

00:07:19 --> 00:07:24
Look closely and notice that some vertices are not exactly symmetrical.

00:07:25 --> 00:07:29
Decrease the Mirror Threshold value to 0.2 and try again.

00:07:30 --> 00:07:32
This time, the effect is perfect.

00:07:33 --> 00:07:39
As far as the middle line of hips vertices go, these need to be affected by three bones:

00:07:39 --> 00:07:45
The hip bone and the two thigh bones, especially when the thighs rotate forward and back.

00:07:46 --> 00:07:48
Select all the middle vertices under the belt.

00:07:49 --> 00:07:51
At this time, they're affected only by the hip bone.

00:07:52 --> 00:07:57
To ensure the vertices are equally affected by the thigh bones, you need to use the Weight tool.

00:07:58 --> 00:08:02
With the vertices selected, select the left thigh bone.

00:08:03 --> 00:08:07
Click the .25 preset button to give it a 25% influence.

00:08:08 --> 00:08:11
The value matters little at this point, you'll change that in a second.

00:08:11 --> 00:08:16
Now select the right thigh and click the .25 preset button again.

00:08:16 --> 00:08:19
The weights are now all over the place.

00:08:19 --> 00:08:27
To fix this problem, select the middle bone in the dialog and give it a 100% influence (preset button 1).

00:08:28 --> 00:08:32
Now select the last bone and give it a 50% influence.

00:08:32 --> 00:08:36
Now each thigh bone has a 50% influence on the vertices.

00:08:37 --> 00:08:42
Finally, select the hip bone and give it a value, such as .75.

00:08:43 --> 00:08:49
The weights are normalized but at least the left and right thigh bones have identical influences on the vertices.

00:08:50 --> 00:08:54
From this point on, you only adjust the hip bone influence on these vertices.

00:08:55 --> 00:09:00
This way, you ensure that the weights coming from both thigh bones remain equal.

00:09:13 --> 00:09:14
Save your file.

00:09:15 --> 00:09:21
Remember that if you make a mistake, you can always revert back to one of the files you downloaded for this tutorial.

00:09:21 --> 00:09:24
In the next movie, you adjust the torso.
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Tags
  • 3ds Max
  • Animation
  • Character
  • 2013
  • Character Animation
  • Workflow
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