Skin Wrapping in 3ds Max - Part 2 - LOD

By
-
Login to Follow
-
Industry
  • Games
Subject
  • Modeling
  • 2012
Products
  • 3ds Max
Skill Level
  • Intermediate
Duration
7 min

Skin Wrapping in 3ds Max - Part 2 - LOD

In this tutorial, learn how to use Skin Wrap to transfer skinning data across multiple LODs (Level-of-Detail) on your original character. This is a huge time-saver as it enables you to quickly create multiple skinned instances of the same character to use in various places in your game engine.


Notes

  • Recorded in: 3ds Max 2012
  • This tutorial is intended for use with 3ds Max version 2012 or higher.

Transcript

00:00:00 --> 00:00:05
Inevitably when you're developing a game, you will have to deal with LODs.

00:00:05 --> 00:00:12
LOD stands for Level-of-Detail. It's a process to define how complex an object is
based on its proximity to a camera.

00:00:13 --> 00:00:17
A character for example needs to be fairly detailed when the camera is very close.

00:00:18 --> 00:00:22
From a little further out, that same character will require only medium detail,

00:00:23 --> 00:00:29
and from a greater distance still, low detail can be used
as your eye wouldn't perceive it from that far.

00:00:30 --> 00:00:35
You can see the difference in poly-count between these three otherwise identical characters.

00:00:36 --> 00:00:42
Using Skin Wrap like in the first movie, you can transfer skinning data
from one character to another.

00:00:42 --> 00:00:49
Typically, a rigger would skin a low-res or a medium-res character
before skin-wrapping a high-resolution model.

00:00:50 --> 00:00:57
In this case however, the character that is already skinned is the more detailed one,
and you'll use Skin Wrap to skin the LODs.

00:00:58 --> 00:01:04
In this particular case, the "hi-res" character is only about 2,000 faces and is easy enough to skin.

00:01:04 --> 00:01:12
If the model were made of half a million faces, then it would have made sense
to skin a lower-res version and then transfer the weights via Skin Wrap.

00:01:13 --> 00:01:18
Select the Medium and Low LODs and relocate them to [0,0,0]

00:01:23 --> 00:01:31
Make sure both LODs are selected; you can use the Selection Set to that effect,
and apply a Skin Wrap modifier to them.

00:01:36 --> 00:01:41
Start with the medium LOD. Notice that the Skin Wrap modifier is instanced.

00:01:42 --> 00:01:45
What you do with the Medium LOD will affect the Low LOD as well.

00:01:46 --> 00:01:54
Make sure the Deformation is set to Face with a 0.001 Falloff
and add the Full Body character to act as a Control object.

00:01:55 --> 00:02:00
It is probably best to select the Full Body character from a list by pressing H.

00:02:04 --> 00:02:08
When the Process is complete, right-click to exit Add mode.

00:02:08 --> 00:02:13
If you want, you can test the skinning by selecting a Biped part and exiting Figure Mode.

00:02:14 --> 00:02:16
You'll find that Skin Wrap worked flawlessly.

00:02:17 --> 00:02:24
This was a little expected in this case, since the LODs and the original character
are really based on an identical structure.

00:02:26 --> 00:02:28
Go back to Figure mode when done.

00:02:29 --> 00:02:37
Ultimately, you would need to convert Skin Wrap to regular skin,
especially if you plan to save individual LODs as separate files.

00:02:37 --> 00:02:43
Because Skin Wrap was instanced, you will get an error message
if you tried to convert Skin Wrap to Skin.

00:02:45 --> 00:02:50
First you need to make the modifier unique for that process to work.

00:03:00 --> 00:03:06
Now you have the Low-LOD and the Medium-LOD independently skinned to the biped skeleton.

00:03:10 --> 00:03:12
But here's the problem:

00:03:12 --> 00:03:17
Your Art Director comes along and decides to make a change to the original character.

00:03:17 --> 00:03:24
The new character is to have a tiny waste and bulging biceps,
and therefore the LODs have to be adjusted accordingly.

00:03:24 --> 00:03:30
So, not only do you need to adjust the original mesh, but also the LODs for that mesh as well.

00:03:31 --> 00:03:38
This is where Skin Wrap really shines: In addition to using it to transfer skin data,
you'll use it as a modeling tool as well.

00:03:39 --> 00:03:45
Before you start making geometry changes, remove the newly applied Skin modifiers from the LODs.

00:03:45 --> 00:03:50
Obviously, these cannot be used anymore if the character's geometry has changed.

00:03:52 --> 00:03:57
Now select both LODs again and apply an instanced Skin Wrap modifier.

00:04:02 --> 00:04:06
Choose the Full Body mesh as a control object one more time.

00:04:07 --> 00:04:12
Make the Skin Wrap modifiers unique but do not convert them to skin just yet.

00:04:17 --> 00:04:21
Now let's see what happens as you start editing the main character's geometry.

00:04:22 --> 00:04:30
Select the Full Body character and in the Modify panel go to Editable Poly > Edge sub-object mode.

00:04:35 --> 00:04:38
Select a horizontal edge around the belly and choose Loop.

00:04:39 --> 00:04:43
Enable Soft Selection and scale the waist down a bit.

00:04:48 --> 00:04:53
Notice that the LODs have followed suit, courtesy of the Skin Wrap modifier.

00:04:53 --> 00:05:00
Skin Wrap is almost acting like a deformation tool for the geometry,
not only to transfer skin weights.

00:05:00 --> 00:05:07
Use the same technique to beef up the biceps or shoulder areas,
and you have a totally new character.

00:05:07 --> 00:05:14
This technique can be used to create variations such as Skinny/Medium/Fat versions
of the same character.

00:05:15 --> 00:05:18
There is however one catch to look out for.

00:05:18 --> 00:05:20
Select either LOD models.

00:05:21 --> 00:05:26
You have to be very careful how you proceed to convert the Skin Wrap modifier to skin here.

00:05:27 --> 00:05:33
Before moving on, choose Edit > Hold. This will enable you to come back to this point
if you encounter a problem.

00:05:34 --> 00:05:41
If you click on Convert to Skin now, you'd be surprised to see
that the LOD has lost the change in geometry information.

00:05:42 --> 00:05:49
This is due to the fact that the geometry change information is stored
into the Skin Wrap modifier, which is now turned off.

00:05:50 --> 00:05:53
Notice what happens when you enable or disable it.

00:05:54 --> 00:06:01
Make sure the Skin Wrap modifier is enabled, right-click it and choose Collapse To.

00:06:02 --> 00:06:09
Click Yes to dismiss the Warning message. Now the geometry change is stored
at the editable poly level.

00:06:09 --> 00:06:13
Repeat the procedure with the Low-LOD.

00:06:23 --> 00:06:30
As you can see, this LOD technique can be very useful
when you need to generate additional characters based on some geometry changes.

00:06:31 --> 00:06:37
In the 3rd and last movie, you'll experiment by adding additional props to an existing character.
Posted By
Tags
  • 3ds Max
  • Modeling
  • 2012
0 Comments
To post a comment please login or register
*Save $70 per month on Autodesk's Suggested Retail Price (SRP) when purchasing 1 year term 3ds Max or Maya subscription.