CityEngine

CityEngine中纹理贴图之道(二)

2

2018-04-02

接着上一篇。

为了让脚本看起来更连贯，无需跳转上一篇，我们从头开始。

/**

 * File: MyTestforBaseTexure.cga

 * Created: 30 Mar 2018 08:16:37 GMT

 * Author: Xiaoyan Mu

 */



version "2017.1"

attr height = 10

attr groundfloor_height = 4

attr floor_height = 3.5

attr tile_width = 3.5



wall_tex        = "facades/textures/brickwall.jpg"

dirt_tex        = "facades/textures/dirtmap.15.tif"

graffiti_tex    = "facades/textures/Graffiti.jpg"

window_tex      = "facades/textures/window.5.tif"



Lot --> extrude(height) Building



Building --> comp(f) {front : Sidefacade}

假设我希望在这面墙上“凿”出窗户，就需要将Sidefacade进行细化切割。贴纹理时也要注意一下新的技巧，也就是在细分表面之前先定义纹理UV，细分之后再用上一篇中提到的贴纹理的方法应用到Wall，这样就可以得到连续的墙体贴图。这样的做的原因在于，CE中的shape都是被不断迭代替换的，如果不在细分之前定义UV，Sidefacade对象在细分之后已经消亡了。

# Sidefacade is modified



Sidefacade -->  

    # Setup texturing

    setupProjection(1, scope.xy, 1.5, 1) 

    setupProjection(2, scope.xy, scope.sx, scope.sy)

    # Divide Sidefacade

 	split(y){ groundfloor_height: Wall | {~floor_height : Floor}* }



Floor -->

	split(x){ 1 : Wall | { ~tile_width : Tile }* | 1 : Wall }            

Tile -->

	split(x){ ~1 : Wall |  2 : split(y){ ~1: Wall | 1.5: Window | ~1: Wall } | ~1 : Wall }	



Wall -->

    # Apply the texture         

    set(material.bumpmap,wall_tex)

    set(material.dirtmap, dirt_tex)

    projectUV(1)

    projectUV(2)

    

Window -->

    offset(0.05) 

    comp(f) { inside: WondowInner | border: WondowFrame }

    WondowInner -->

	  setupProjection(0, scope.xy, scope.sx,  scope.sy) 

	  texture(window_tex)

	projectUV(0)      

      WondowFrame -->

      extrude(0.1)

material.opacitymap

material.opacitymap 通道可以用于控制纹理的透明度。

继续上面的例子，如果希望做出透明的窗户效果，可以将Window的代码替换为如下的样子。

Window -->

    offset(0.05) 

    comp(f) { inside: WondowInner | border: WondowFrame }

    WondowInner -->    

      setupProjection(4, scope.xy, scope.sx,  scope.sy) 

      set(material.opacitymap, window_tex)

      projectUV(4) 

    WondowFrame -->

    extrude(0.1)

material.specularmap
为了虚拟现实，窗户玻璃来点反光效果吧。

上代码：

Window -->

    offset(0.05)   

    comp(f) { inside: WondowInner | border: WondowFrame }

    WondowInner -->   

	 setupProjection(0, scope.xy, scope.sx,  scope.sy) 

	 texture(window_tex)

	 projectUV(0)

	 set(material.specular.r, 1) 

     set(material.specular.g, 1)   

     set(material.specular.b, 1)

	 set(material.shininess, 2)	

	 setupProjection(3, scope.xy, scope.sx,  scope.sy)

	 set(material.specularmap, specular_tex)

	 projectUV(3)

    WondowFrame -->

    extrude(0.1)