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Honours Graphics 2008
Session 12
Today’s focus
• Non-photorealistic rendering
• …other topics requested in class…
Non-photorealistic rendering
• Sometimes graphics applications require the use of non-photorealistic rendering to achieve some effect (artistic expression, alternate spectrum rendering, etc)
• For example: cel-shading, pencil etching, calligraphy (japanese big brush style), etc
Non-photorealistic rendering
False color imaging
Non-photorealistic rendering
Pencil sketching Quake
Non-photorealistic rendering
Artistic impression
Non-photorealistic rendering
Calligraphy (Japanese Big Brush)
Non-photorealistic rendering
Cel-shading
Cel-shading
• Also “cell-shading” and “cartoon shading”
• 3D impression of models in traditional cartoon-style lighting, along with pronounced contouring
Cel-shading, how-to
• Quite easy to do even on older graphics hardware
• Two parts: lighting and contouring
Cel-shading, how-to, cont.
• Lighting follows the classic diffuse model, but the resultant color value is instead indexed into a one-dimensional array; instead of
a blocky lighting array is used
Cel-shading, how-to, cont.
• Contouring is done through inverse backface removal
• First render model normally using cel-lighting
• Set to render black wire-frame• Set lines to render thick• Set to cull front faces• Render model (z-buffer handles
elimination of invisible contours)
Cel-shading, result
Topic defined by students
• …