This sample application demonstrates the use of the
two new 3-tuple stream types, UDEC3 and DEC3N, which can be used to
store normals or other 3-tuples in a quantized form. Normals, tangents, binormals and
other 3-tuple vertex components can often be specified at reduced precision
without introducing noticeable artifacts, reducing the amount of memory
and memory bandwidth they consume. This application creates three
sphere meshes, one with UDEC3 normals, one
with DEC3N normals and one with traditional
FLOAT3 normals.
Developers should take note of the PACK_UDEC3() and PACK_DEC3N() packing
routines in the sample application as well as the corresponding "unpacking"
instruction which must be executed inside the SimpleUDEC3.vsh shader
to put the normal vectors into the intended -1 to +1 range.
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