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

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 …