In CG film production, we rely on captured HDRI maps to drive realistic lighting response from the environment. Many of these HDRI Environment Maps, or Lightmaps, used in production by either on-set capture or purchased through a 3rd party, contain clipped high values, especially the sun. When using clipped maps from a look development process through to lighting on a production, inconsistency in material settings result, creating unrealistic and inconsistent responses in materials.
One major source for clipping these maps for use in production and the reason they have been so prevalent has been due to non importance-sampled shader setup requiring too many samples to practically deal with unclipped map sources. With Renderman’s introduction of Physically Plausible Shading, and other proprietary importance-sampled shading setups becoming more common, it has become more practical and necessary to use properly captured and unclipped HDRI’s.
In our presentation we test multiple unclipped HDRI Lightmaps using fully raytraced importance-sampled shading, and compare with clipped HDRI maps found in production.
|
Christos Obretenov, Co-owner and Shader Developer, Lollipop Shaders, http://lollipopshaders.com
Educated at Simon Fraser University in Computing Science and Computer Graphics, Christos Obretenov started contributing to the Animation and Film industry at Mainframe Entertainment in conjuction with Simon Fraser University. He continued his career by designing and developing shading software for Walt Disney's "The Wild" feature film, followed by shading and lighting for Superman Returns, Spider-Man 3, Beowulf, Christmas Carol, and Mars Needs Moms feature films. Recently co-founding LollipopShaders.com, Christos develops procedural solutions to shading and lighting, currently experimenting with Physically Plausible Shading. He currently resides in Vancouver, Canada.
|