Depth to Cluster.nb

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This mapping step is necessary to implement Clustered Forward Rendering.\n\n\
It is important to note that the conversion relies on using a linear depth \
value.\nThis value can be either computed from the depth buffer (see the \
linearZ function),\nor come directly from an eye space position in the case \
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types of scenes\nthat will be lit using the Clustered Forward Rendering \
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To implement the special cluster, we simply need to\nreplace the near plane \
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