Vector Displacement in the Sculpting Workflow - Game Development Tools - page 228

Figure 16.6. A sculpt of an organic structure (left) at 1.6 million polygons and a file
size of 200 MB (.obj format) compared to the same structure stored as a (.tif) vector
displacement map (right) at 1024 × 1024 resolution and a file size of 17 MB. (VDM
exposure adjusted in Mudbox Image Browser). (See Color Plate XIII.)
Smaller data footprint. Geometric details stored in the form of 32-bit (per chan-
nel) floating-point images are a much smaller and ecient dataset than a directory
of high-resolution models. Large datasets can result in bloated directories and im-
pact the pipeline negatively. This is especially true with high-resolution geometry
(see Figure16.6 , whereVDMscanbestoredinavarietyofimageresolutions:
smaller resolutions for stamps and stencils, and, when necessary, larger resolutions
for complete objects (characters, props, environments, etc.). Furthermore, VDMs
can be applied in a manner that allows for quicker scaling and placement as well
as control over blending into the existing surface of the mesh.
UV-less workflows: Ptex. The future of workflows that do not rely as heavily on
UVs provides enormous potential for the use of vector displacement in a sculpting
workflow. Developed for production use at Disney Animation Studios, Ptex is a
new texture-mapping method that requires no explicit parameterization [Burley
and Lacewell, 08]. Ptex is free of tedious UV setup and allows for the easy transfer
of details between arbitrary meshes. Mesh topology and textures are free to change
throughout a pipeline without the fear of details becoming invalidated. Ptex al-
lows sculpted details to be stored and re-applied to a mesh even after substantial
topological changes [Burley and Lacewell, 08].
Hardware-accelerated tessellation. Hardware companies are continually push-
ing the limits of graphics processing power and, as a result, the next-generation
GPU will handle much higher geometry resolutions. Hardware-accelerated tessel-
lation will allow for the rendering of dense subdivision surfaces in real time. This
allows for greater levels of detail within a game engine or any real-time rendering en-
vironment. Tools, such as Mudbox, allow for the creation of highly detailed meshes
and VDMs to store geometry data in a 2D image format. The use of VDM images