Game Development Reference
In-Depth Information
format is to work with simple planes. This geometry can be created within Mudbox
or imported from another digital content creation package (i.e., Maya, 3ds Max,
or Softimage). Taking advantage of the tools and layer system within Mudbox,
the details can then be sculpted at a variety of subdivision levels. The images in
Figure16.4
illustratetheprocessbywhichdetailissculptedonaplanethathas
been subdivided many times.
Extracting vector displacement maps.
Once the high-resolution details have
been sculpted, the map extraction process within Mudbox could not be easier. The
process
involves
accessing
the
extraction
options
menu
(Maps
>
Extract Texture Maps
New Operation) and selecting Vector Displacement Map
from the Map Generation list (see
Figure 16.4(d)
). In the menu box, we simply
define the low-resolution mesh as the target (where you want the details to transfer
to) and the high-resolution mesh as the source (where you want the details to trans-
fer from). The target and source geometry must share identical topology where,
either the target is a lower subdivision level from the same model or another model
that shares the exact same topology. For creating VDMs that are storing details
to be accessed in a sculpting session, it is a good idea to use a separate version of
the base mesh, in this case, the simple plane. This insures a flat, untouched base
plane for the target mesh. This can be accomplished by either creating another
plane within Mudbox or by importing a new version (see
Figure 16.4(c)
)
.
To define the properties of the image to output, we simply select an Image Size
(resolution up to 8K), Antialiasing (if required), the Vector Space (specifies the
coordinate space for calculating the output map) and, a Base File Name (the name
and location of our output image). The Base File Name is output as 32 bits per
channel by default and the file type is (currently) limited to .tif, .exr, and .ptx
(Autodesk Mudbox 2011 Subscription Advantage Pack). The final output filename
>
Applying VDMs.
As with regular textures, displacements or reference images, ac-
cessing VDMs in Mudbox is just as easy. The built-in Image Browser is a 32-bit
image viewer and can be used to preview a library of VDMs. As with 32-bit HDR
images, the exposure can be adjusted for viewing the VDM using the “+” and “
”
hotkeys (see
Figure 16.6
)
. From the Image Browser, VDMs can be viewed and
selected as a stamp or stencil to work with directly in the 3D viewport by selecting
the Set Stamp or Set Stencil commands. Stamps and stencils can also be added to
the existing libraries in the tabbed trays at the bottom right of the 3D viewport
by accessing the menu (the arrow icon) and selecting “Add...”. This allows for
several VDM stamps and stencils to be stored in their appropriate trays for quick
and repeated access throughout a sculpting session.
To apply VDMs, the mesh will need to be subdivided to a suitable resolution
to utilize the details stored within the VDM image. VDMs can be used with any
of the primary sculpt tools within Mudbox; however, the main sculpt brush will
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