Unity組件：Edge Detect Effect Normals 法線的邊緣檢測(cè)特效

This version of the Edge Detect image effect creates outlines around edges by taking the scene geometry into account. Edges are not determined by colour differences but by the surface normals and distance from camera of neighbouring pixels (the surface normal is an "arrow" that indicates the direction the surface is facing at a given pixel position). Generally, where two adjacent pixels have significantly different normals and/or distances from the camera, there is an edge in the scene.

該邊緣檢測(cè)的圖像特效是通過(guò)場(chǎng)景中物體的幾何信息來(lái)將其輪廓線抽取出來(lái)。邊緣不僅由顏色的差異來(lái)決定，同時(shí)也由相鄰像素所對(duì)應(yīng)的法線朝向和離相機(jī)的距離來(lái)決定。一般來(lái)說(shuō)，當(dāng)兩個(gè)相鄰像素?fù)碛忻黠@不同的法線朝向或距相機(jī)距離時(shí)，這就是場(chǎng)景中的一個(gè)邊緣。

As with the other image effects, this effect is only available in Unity Pro and you must have the Pro Standard Assets installed before it becomes available.

和其他圖像特效一樣，該特效只能在Unity Pro上進(jìn)行使用，并且在使用之前必須安裝Pro Standard Assets。

Scene without edge detection 沒(méi)有邊緣檢測(cè)效果的場(chǎng)景

The same scene showing the detected edges 同樣場(chǎng)景有邊緣檢測(cè)效果

This effect uses the ImageEffectOpaque attribute which enables image effects to be executed before the transparent render passes. By default, image effects are executed after both opaque and transparent passes have been fully rendered.

該特效使用了ImageEffectOpaque屬性，該屬性使圖像特效在渲染透明物體通道之前執(zhí)行。默認(rèn)情況下，圖像特效都是在場(chǎng)景中實(shí)體和透明物體全部渲染完成后進(jìn)行的。

Properties 屬性

• Mode 模式
  Chose between Thin and Thick. Thick will take more samples into consideration to construct outlines.
  在粗細(xì)之間進(jìn)行選擇。粗表示使用更多的采樣點(diǎn)來(lái)生成輪廓線
• Edge Sensitivity
  邊緣敏感度
• Depth 深度
  The minimum difference between the distances of adjacent pixels that will indicate an edge.
  相鄰像素的深度最小差異。大于該差異，則認(rèn)為存在邊。
• Normals 法線
  The minimum difference between the normals of adjacent pixels that will indicate an edge.
  相鄰像素的最小法線朝向差異。大于該差異，則認(rèn)為存在邊。
• Background options
  背景選項(xiàng)
• Edges only 僅邊緣
  Blend the background with a fixed color.
  將一個(gè)固定顏色與背景進(jìn)行混合
• Background 背景
  The color used when Edges only is > 0.
  僅當(dāng)邊大于0時(shí)使用這個(gè)顏色。

Hardware support 硬件支持

This effect requires a graphics card with pixel shaders (2.0) or OpenGL ES 2.0. Additionally, depth texture support is required. PC: NVIDIA cards since 2004 (GeForce 6), AMD cards since 2004 (Radeon 9500), Intel cards since 2006 (GMA X3000); Mobile: OpenGL ES 2.0 with depth texture support; Consoles: Xbox 360, PS3.

這個(gè)特效需要顯卡擁有像素著色器（2.0）或者OpenGL ES 2.0。臺(tái)式機(jī)：2004年以后的NVIDIA顯卡（GeForce 6），2004年以后的AMD顯卡（Radeon 9500），2006年以后的Intel卡（GMA X3000）；移動(dòng)設(shè)備：OpenGL ES 2.0并支持深度紋理；控制臺(tái)： Xbox 360、 PS3。

All image effects automatically disable themselves when they can not run on end-users graphics card.

所有圖像特效如果無(wú)法在用戶顯卡上運(yùn)行時(shí)將會(huì)自動(dòng)被關(guān)閉。