Facial Skin Layered
Mapping
Part 9.1 – The Back to the Back
Before You Begin
Have your Front Section work file and the
SkinBackSectionRawGuide0.tga you created in Part 3.2 open in Photoshop. Have your model open in AM. If needed open the Back Section flattening
action.
Introduction
Unfortunately I make a slight mistake in the
beginning of this tutorial and had you produce guides for the back section
without aligning the splines to the front section but this isn’t too bad. The must do to things so that there is no
seam between the maps on the Front Section and the Back section:
- We
must match the Back Section splines to the Front Section splines.
- We
must bring each map from the Front Section directly over to the Back
Section using the Clone tool.
If this were a more visible area we might also use
gradient blended alpha channels but
these seams will be covered partially covered by shirt colors and/or hair and
are also in an area that will rarely if ever been seen.
- In the FrontSectionWork[999].psd file (where [999] is the version
number of your latest file) hide everything except for the Background
(Figure 9.1.1).

Figure 9.1.1
- Do Image->Duplicate and flatten the duplicate.
- In the flattened duplicate use the Polygonal Lasso Tool to select
the left side patches that will meet with the Back Section for two rows of
patches inward (Figure 9.1.2).

Figure 9.1.2
- Switch
to the SkinBackSectionRawGuide0.tga image and duplicate it. Close the original. Select the Move tool and drag your
selection right over onto the duplicate of the SkinBackSectionRawGuide0.tga
image. This will create a new layer
with your selection in it. Name
this layer Right Guide.
- The
right side you selected will connect to the right side of the Back Section
so with the move tool still selected move your selection to the right of
the Back Section Guide (Figure 9.1.3).

Figure 9.1.3
- Before
going further save this file to the Maps/Head/wip folder as
BackRotoWork001.psd.
- Next
we want to remove the background leaving only the mesh. Hide the background then with the Right Guide
layer selected and using the eyedropper tool select the background color
then do Select->Color Range.
Adjust the Fuzziness until you can see the mesh and click okay
(Figure 9.1.4).

Figure 9.1.4
- Firmly
press <Delete> and then unhide the background. You should still have the mesh
selection. If not use undo and
repeat step 6 adding more Fuzziness.
- Control
click the Right Guide layer in the Layers pallet to select all of the
pixels in that layer and go into Free Transform mode (<ctl>t) and
rotate the select until it is aligned and fitted next to the Back
Section. If needed resize the
selected mesh (holding down the <shift> key so that the aspect ratio
is maintained) until the ends of the selection mesh line up with the Back
Section mesh (Figure 9.1.5).

Figure 9.1.5
- Repeat
this process to line up the other side naming the new layer Right Guide
(Note: when you select and delete the background only the new layer you
are removing it from should be visible).
You should wind up with something roughly like Figure 9.1.6.

Figure 9.1.6
- Save.
- Select
the Right Guide – this should be the top layer – and merge down
(<ctl>e) so that you combine the Right Guide and Left Guide layers.
- Now we want to color this thing so that
we can see it in A:M clearly.
Select magenta (or whatever color will work for you) from the
Swatches pallet to color the guide
splines in the Right Guide layer.
- Control click the Right Guide layer in
the Layers pallet to select all the pixels and the press
<alt><backspace> to fill it with the foreground color.
- Hide
the Right Guide layer and select the Background. Using the eyedropper tool select the
background color. Do Select->Color Range and adjust the fuzziness until the
mesh can be seen. Click okay.
- Select
black from the Swatches pallet and hit <alt><backspace>.
- Invert
the selection (<ctl><shift>i).
Select red from the Swatches pallet and press
<alt><backspace>.
- Save.
- Unhide the Right Guide layer and flatten
the image. The crop the image down
so that there is a slight boarder around the mesh. You should have something like Figure
9.1.7.

Figure 9.1.7
- Save
this in your wip folder as BackAlignmentGuide.tga.
- Close
this file. Close the flattened Work
file duplicate without saving.
- You
should still have the FrontSectionWork file open in Photoshop. Go ahead and close this as well.
- Switch
to A:M, select the BackSection and hide the rest.
- Open
the Back Section Flatten action, go to muscle mode and zoom to
extents. Now set the zoom factor to
the zoom factor you created back in Part 3.1.
- In
the PWS right click on the action and select New->Rotoscope the select
‘Other’ and read in the BackAlignmentGuide.tga file. It may go right into position – if not,
move and resize until you have it aligned to the mesh then unselect it and
make the rotoscope ‘un-selectable’.
- What we need to do is adjust the
horizontal splines so that they are lined up with their corresponding
Front Section splines however we do not want to disrupt the vertical
positions too much. Select a row of
horizontal spines and arrow up or down until the one side is aligned with
its corresponding spline on the guide (Figure 9.1.8). Using guides can help. Hit ‘r’ to go into rotate mode and move
the pivot point to the cp you aligned (Figure 9.1.9) and then rotate until
the other side is aligned (Figure 9.1.10). If you have to rotate the horizontal
spline too much the mesh can become skewed too much and you may need to
scale it horizontally and move it from side to side to get it within a
reasonable position again.

Figure 9.1.8

Figure 9.1.9

Figure 9.1.10
- Proceed
until each horizontal spline is aligned.
You should wind up with something like Figure 9.1.11.

Figure 9.1.11
- Save the project file.
- Now hide the rotoscope, zoom to extents
(to center it) then plug in the zoom factor you used before so the scale
will be right.
- Do a screen capture and paste it into
Photoshop.
- Now as a sanity check well compare the
size of the screen capture to the Front Section. Select the background color using the
Eyedropper tool and do Selection->Color Range.
Adjust the Fuzziness until the mesh barely shows and click Okay.
- Invert
the selection (<ctl><shift>i) and place the selection in a new
layer (<ctl>j).
- Now
open and switch to the SkinFrontSectionWork.psd and make only the
Background visible and select it.
- Returning
to the screen capture image select the Move tool and drag and drop the new
layer into the SkinFrontSectionWork.psd image. This will create a new layer above the
Background.
- Using
the Free Translate tool rotate and compare the mesh of the back section to
the edges it meets in the Front Section.
If it is not the same size on both edges adjust it so that it is. Once you have sized it rotate it back to
the original vertical position and select okay.
- Using
the move tool drag this back to the screen capture image – this creates a
new layer.
- Flatten
the image.
- Now you need to use this guide to create
a new work file. You can either
refer back to Part 3.2 and follow the steps or use
the Photoshop action file for this or, you can adjust the BackSectionWork
file you already have. In either
case you need to make sure that you have plenty of room on both sides of
the guide.
Go to Part 9.2 –
Cloning the Maps and Checking the Seam