shader

Glass scene rendered in POV-Ray, demonstrating radiosity, photons, focal blur, and other photorealistic capabilities

當 Opensource 裏頭，有悠久歷史，且常常是學習電腦圖學（Computer Graphics）中的算圖（Rendering）領域的學子，會去拿來當作一個練習平台的 POV-Ray (@Wikipedia)，遇上了工業上赫赫有名的 RenderMan 標準時，就誕生了 POV-Man 這個計畫。

就個人來說，會忍不住想給 POV-Ray 灌上有點神祕，學術上比較高貴的感覺，原因無它，就因為它讓我覺得很遙遠，無從著手，而且除了看到使用它算出來的圖的品質不錯以外，完全不曉得可以拿它來幹麻。

右邊這一張圖，是使用 POV-Ray 算出來的圖，它有 raytracing 特有的反射（reflection）、折射（refraction）和聚焦（caustics，是這樣翻的嗎?）。這張圖同時還算出來景深（Depth of Field）、軟軟的影子（soft shadow，應該不是這樣翻的吧）。

SHADERS

Clearly, shaders play a crucial creative role in defining the appearance of a CG production. RenderMan has been adopted by many leading studios because it allows special purpose shaders to be added to those that already exist.

Individual shaders are small sub-routines (functions) written in a specialised programming language called the Pixar Shading Language. The language enables new shaders to extend the creative possibilities of the renderer; it allows computer artists to find endless ways of controlling the appearance of a 3D scene through the use of custom shaders. The only limit is their imagination, their ability to write new, or adapt existing shaders and their creative flare at adjusting the parameters that control the visual effect of a shader.

In some respects RenderMan shaders are analogous to plugins for, say, PhotoShop and AfterEffects. Plugins for those applications provide extra functionality to their host program. Likewise, shaders "work" within the environment of a renderer.

上述段落的出處：http://www.fundza.com/rman_shaders/overview/overview.html

對於第二段的最後一句的感受很強烈，強烈到一種像是被給了一巴掌似的，那種明明早就知道的情況，但卻無力做好，然後被指著說還沒有反駁的立足點。我想成為一位夠擔當的 TD（Technical Director），於是常常徘徊在「技術 spec 的瞭解與專研」和「美感 sense 與選對工具並好好活用」之間，這感覺十足惱人，非常惱人。管它的，就是學好學精一樣東西就對了。