This video is about parametric fitting.
I have taken the simple tank-top from the fitted Mesh video series for demonstration…


Step one: prepare the environment.

Actually i just set the Avastar rig to fitted mesh mode right from the beginning of the project.

Step two: bind the attachments as usual.

In this case i use automatic weights-from-bones as my initial weighting.

Then i enable the Second Life Appearance sliders.
Now we are done with the binding part.

Step three: Inspect the results.

By now we have weight maps only for the classic bones.

I recommend that you now proceed with…

step 4: adjusting the weightmap configuration.

In this step you will tweak the weight maps and possible even the mesh
such that your model animates nicely with the classic bones and with the current shape.

And please note… this step in your workflow can actually take a lot
of time, depending on the complexity of your mesh.

i will skip this step for now,
and i expect you have prepared your initial classic weightmaps
so that they work nicely for your mesh on your current shape.
SO let us now enable the fitted mesh.

At this time you probably have already setup your Blender for weighting.
However, let me quickly step over to…

Step 5: Setup my own environment for fitting.

In the rigging panel i select the preset for skinning.
I also prefer to use stick mode, so i can better inspect the weight maps,
Then i set the display mode to Solid.

Step 6: inspect the initial weights on our model.

We see currently we have only classic bone weights
while all fitted Mesh bones are still not weighted at all.

ok, we now can close the rigging panel, as we do no longer need it.

Step 7: Enter the fitting panel.

The fitting panel contains 2 groups of sliders,
the group at the bottom is the list of classic and fitted mesh bone pairs.
Here you can find up to 19 entries. And each of these entries is related to 2 bones…
a Basic SL Bone
and a corresponding Collision Volume Bone.
So for each entry in this list we will find either one or 2 corresponding weight maps in the vertex groups list of our object.
And since we have not yet created any Fitted Mesh weights
we only see the weight maps of the classic bones at the moment.
We get back to this slider group in a minute.

ok, The other group of sliders is related to the physics bones.
These are a set of 7 Collision Volume Bones which have no corresponding classic Second Life bone. But these bones are animated by the Avatar physics.

And the strength of the physics behavior is controlled by weight maps as well,
so we have added a Generator for creating the physics weights.

And we proceed to…

Step 8: Generate the physics weights.

The strength sliders are actually split into 2 parts.
The part from the middle to the left side controls how much the mesh is affected by the Avatar physics.
And the part from the middle to the right side suppresses small weight values in favor of the higher values.

Please note… by default we have disabled the physics only for the handles.
But we also can disable the other physics bones if we like.
In fact we want to disable as many sliders as ever possible,
because we are allowed to use no more than 4 weights for each vertex.

But each physics weightmap adds one extra weight.
So you can easily define more then 4 weights per vertex
And this is not supported in Second Life.

So… you need to keep this in your mind,
otherwise you certainly get a few surprises when you later upload your mesh to your virtual world.

Now back to our model…
well, watching how the sliders affect the weights on the attachment is nice
but we actually want to see how the mesh changes with different slider values.
For this purpose we have added an automation button at the bottom of the fitting section.

When this button is enabled, then any change of the sliders will be instantly propagated to the mesh
thus you can see how the sliders settings affect the shape.
However, nothing happens. Why that
This is so because the Collision Volume Bones actually have no influence at all
when the Character is in its Default Shape. Hence…

Step 9: Define a working Shape.

We have to get out of the default Avatar shape,
and change the Appearance slider values.
We can do this in the Avatar appearance Slider section.

Lets open the section for the torso,
and then move the breast slider up to 100.

Step 10: Interactive Tweaking of the physics Volume sliders

Here we inspect how the mesh deforms while we adjust the physics strength sliders.
Note that this operation consumes a lot of resources and is rather slow.

So we see… the Mesh does not move exactly in the same way as the default Avatar.
Hence we need to fix that.
The easiest fix is to tweak the mesh itself.
I show you now how you can do this in a very straight forward way.

Step 11: Tweak the mesh

ensure you have the appearance slider set to its maximum value
enter edit mode,
then just edit the attachment mesh until it fully covers your avatar

And also note, the physics strength sliders are just a weighting tool.
So, these sliders are used only to setup and tweak the weights for your attachments.
You also do not find these sliders in the Avatar Appearance editor.

Actually you even can later tweak the weight maps as usual with any of the other available weight tools.

So after some mesh editing we are satisfied with the results,
now we need to make our changes permanent.
In the Avatar appearance section we find the button… Bake to Mesh.

and we proceed with…

step 12: Fitting the Bones

Now lets take care of the belly.
right now there is only one weightmap for the Torso bone.
and the corresponding Collision Volume is not weighted.
Because of this we will see the mesh is not affected when we move the Avatar Appearance Slider for the Belly Size.

So, lets look at the Bone pair sliders.
When you move the Belly slider
then Avastar gradually moves weight from the classic Second Life torso bone to its corresponding collision volume Bone, the Belly.
Thus the collision Volume Bone takes over the control.
However, the good news is
this operation should not affect your animation by any means.
So you can fully concentrate on the slider settings without need to worry about breaking your animations.

For the Belly we see that even pushing the Slider to full strength
is not enough.
This is due to the Pelvis bone pair.
So… lets move the Pelvis slider as well.

Now we again have an issue.
The attachment shape is still not exactly matching to the Avatar shape.
And here is one method to get this fixed.

Step 13: Tweek the Mesh.

well, we did this before, when we adjusted the mesh to work nicely with the breast size-slider.
Just open up the Mesh editor, and tweak the vertices,
until the mesh fits nicely to your current shape.

And when you are satisfied with the tweaks
Then call the Bake-to-Mesh function again
just as we did before when we tweaked the mesh to match the breasts.

Step 14: Final inspection.

When you now move the sliders back to the default shape,
then you see the mesh has changed a bit,
but your benefit is
the mesh now behaves much nicer regarding the appearance sliders.

Of course this is not a perfect method,
and there is still a lot to do before you get a perfectly fitted mesh.
But the parametric fitting tool should give you a much better starting point for your detail work compared to what we had up until now.

Before i end this video, let me point you to another new feature…
Fitting Presets.

Step back to the fitting panel.
At the top of this panel, you see A Fitting Presets Selector.
Here you can store your fitting configuration.
this basically allows you to create as many configurations as you like and recall them in a snap.
We have added 2 commonly useful presets…
fully classic
and fully fitted.

The names of these presets should be self explaining.

Thank you for watching, and have a nice day.