(resolution in dpi, 10--1200) \[ L_o(x,\vec{w}) = L_e(x,\vec{w}) + \int_\Omega f_r(x,\vec{w}',\vec{w}) L_i(x,\vec{w}') (\vec{w}' \cdot \vec{n}) d\vec{w}' \]

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