Rendering学習日記

• python cgkit
• 2010.11.23 Tuesday

「実践CGへの誘い」p.31
Listing 2.7


>list27.py
オブジェクトインスタンスを利用しようと組んだら、以下のエラー
3DL ERROR P1051: [C:0]: invalid context for 'RiTransformBegin'
3DL ERROR P1051: [C:0]: invalid context for 'RiRotate'
3DL ERROR P1051: [C:0]: invalid context for 'RiTransformEnd'

いろいろと調べたら、cgkitでは、
obj = RiObjectBegin()
RiSphere(0.5,-0.5,0.5,360)
RiObjectEnd()
RiObjectInstance(obj)

と記述しているが、これは問題ない。

cube = RiObjectBegin()
UnitCube()
RiObjectEnd()
問題は、UnitCube()
「実践CGへの誘い」によれば、物体の記述に、ジオメトリ変換を記入していると無視される。よってUnitCube()は、一番最初にやった面のみを記述する定義を用いる。

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• python cgkit
• 2010.11.23 Tuesday

できました。よく読まないといけません。
UnitCube()を最初に使った定義のものに戻しています。

「実践CGへの誘い」p.32
Listing 2.7

オブジェクトインスタンスを利用したサンプルです。
ありがとうございます。

#list27.py

#/* Copyrighted Pixar 1989 */

#/* From the RenderMan Companion p. 32 */

#/* Listing 27c A more efficient color cube */

#/* 

# *   ColorCube(): create a unit color cube from smaller cubes 

# *   Parameters:

# *    n: the number of minicubes on a side

# *    s: a scale factor for each minicube

# */



import cgkit.cri

from cgkit.cgtypes import *



# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



L= -.5      #* For x: left side     */

R=  .5      # /* For x: right side    */

D= -.5     #  /* For y: down side     */

U=  .5     #  /* For y: upper side    */

F=  .5     #  /* For z: far side      */

N= -.5     #  /* For z: near side     */



#/* UnitCube(): define a cube in the graphics environment */

def UnitCube():

    Cube=[

        [ [L,D,F],  [L,D,N],  [R,D,N],  [R,D,F] ],   #/* Bottom face  */

        [ [L,D,F],  [L,U,F],  [L,U,N],  [L,D,N] ],   #/* Left face    */

        [ [R,U,N],  [L,U,N],  [L,U,F],  [R,U,F] ],   #/* Top  face    */

        [ [R,U,N],  [R,U,F],  [R,D,F],  [R,D,N] ],   #/* Right face   */

        [ [R,D,F],  [R,U,F],  [L,U,F],  [L,D,F] ],   #/* Far face     */

        [ [L,U,N],  [R,U,N],  [R,D,N],  [L,D,N] ]    #/* Near face    */

    ];

    for i in range(6):

        RiPolygon(P=Cube[i])



def ColorCube(n, s):

    if n<=0:

        return

    

    cube = RiObjectBegin()

    UnitCube()

    RiObjectEnd()

    

    RiAttributeBegin()

    RiTranslate(-.5, -.5, -.5 )

    RiScale(1.0/n, 1.0/n, 1.0/n)

    color=[0,0,0]

    for x in range(n):

        for y in range(n):

            for z in range(n):

                color[0] = (x+1)/float(n)

                color[1] = (y+1)/float(n)

                color[2] = (z+1)/float(n)

                RiColor(color)

                RiTransformBegin()

                RiTranslate (x+.5, y+.5, z+.5)

                RiScale(s, s, s)

                RiObjectInstance(cube)

                RiTransformEnd()

    

    RiAttributeEnd()





color = ( .2, .4, .6 )



RiBegin(RI_NULL);      #/* Start the renderer */

RiDisplay("colormain2.tiff", RI_FILE, "rgb", RI_NULL)

RiFormat(512, 384, -1.0)

RiShadingRate(1.0)

RiLightSource("distantlight", RI_NULL)

RiProjection(RI_PERSPECTIVE,RI_FOV,65)

RiWorldBegin()

RiSides(1)   # /* N E W */

RiTranslate(0.0, 0.0, 1.5)

RiRotate(30.0, -1.0, 0.0, 0.0)

RiRotate(30.0, 0.0, -1.0, 0.0)

RiColor(color)     # /* Declare the color */

ColorCube(4, .8)   #/* Define the cube */

RiWorldEnd()

RiEnd()            #/* Clean up after the renderer */

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• python cgkit
• 2010.11.23 Tuesday

■簡単なアニメーション
６０フレーム出力してみました。
「実践CGへの誘い」p.34
Listing 2.8を改良しました。
Python便利ですね。
ありがとうございます。

#list28change.py

#/* Copyrighted Pixar 1989 */

#/* From the RenderMan Companion p. 34 */

#/* Listing 2.8  A simple animation  */

#/* 

# *   ColorCube(): create a unit color cube from smaller cubes 

# *   Parameters:

# *    n: the number of minicubes on a side

# *    s: a scale factor for each minicube

# */



import cgkit.cri

from cgkit.cgtypes import *



# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



L= -.5      #* For x: left side     */

R=  .5      # /* For x: right side    */

D= -.5     #  /* For y: down side     */

U=  .5     #  /* For y: upper side    */

F=  .5     #  /* For z: far side      */

N= -.5     #  /* For z: near side     */



#/* UnitCube(): define a cube in the graphics environment */

def UnitCube():

    Cube=[

        [ [L,D,F],  [L,D,N],  [R,D,N],  [R,D,F] ],   #/* Bottom face  */

        [ [L,D,F],  [L,U,F],  [L,U,N],  [L,D,N] ],   #/* Left face    */

        [ [R,U,N],  [L,U,N],  [L,U,F],  [R,U,F] ],   #/* Top  face    */

        [ [R,U,N],  [R,U,F],  [R,D,F],  [R,D,N] ],   #/* Right face   */

        [ [R,D,F],  [R,U,F],  [L,U,F],  [L,D,F] ],   #/* Far face     */

        [ [L,U,N],  [R,U,N],  [R,D,N],  [L,D,N] ]    #/* Near face    */

    ];

    for i in range(6):

        RiPolygon(P=Cube[i])



def ColorCube(n, s):

    if n<=0:

        return

    

    cube = RiObjectBegin()

    UnitCube()

    RiObjectEnd()

    

    RiAttributeBegin()

    RiTranslate(-.5, -.5, -.5 )

    RiScale(1.0/n, 1.0/n, 1.0/n)

    color=[0,0,0]

    for x in range(n):

        for y in range(n):

            for z in range(n):

                color[0] = (x+1)/float(n)

                color[1] = (y+1)/float(n)

                color[2] = (z+1)/float(n)

                RiColor(color)

                RiTransformBegin()

                RiTranslate (x+.5, y+.5, z+.5)

                RiScale(s, s, s)

                RiObjectInstance(cube)

                RiTransformEnd()

    

    RiAttributeEnd()





color = ( .2, .4, .6 )



NFRAMES = 60     #/* number of frames in the animation */

NCUBES = 5       #/* # of minicubes on a side of the color cube */

FRAMEROT = 3.0   #/* # of degrees to rotate cube between frames */





RiBegin(RI_NULL)    #/* Start the renderer */

frame = 1

for frame in range(frame,NFRAMES+1):

    if len(str(frame))==1:

        print "anim00"+"%d.tif" % frame

        filename="anim00"+"%d.tif" % frame

    elif len(str(frame))==2:

        print "anim0"+"%d.tif" % frame

        filename="anim0"+"%d.tif" % frame

    else:

        print "anim%d.tif" % frame

        filename="anim%d.tif" % frame

    

    RiFrameBegin(frame)

    RiLightSource("distantlight", RI_NULL)

    #/* Viewing transformation */

    RiProjection("perspective", RI_NULL)

    RiTranslate(0.0, 0.0, 1.5)

    RiRotate(40.0, -1.0, 1.0, 0.0)

    

    RiDisplay(filename, RI_FILE, RI_RGBA, RI_NULL)

    RiFormat(512, 384, -1.0)

    RiShadingRate(1.0)

    RiWorldBegin()

    RiSides(1);  #/* N E W */

    scale = (NFRAMES-(frame-1)) / float(NFRAMES)

    RiRotate(FRAMEROT*frame, 0.0, 0.0, 1.0)

    RiSurface("matte", RI_NULL)

    ColorCube(NCUBES, scale)        #/* Define the cube */

    RiWorldEnd()

    RiFrameEnd()



RiEnd()

出力画像はこちらを参考にしてください。

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• python cgkit
• 2010.11.23 Tuesday

「実践CGへの誘い」p.61
Listing 4.1

基本プリミティブの表示をします。いろいろと工夫できますね。

#list41.py

#/* Copyrighted Pixar 1989 */

#/* From the RenderMan Companion p. 61 */

#/* Listing 4.1  Routine generating quadric surfaces shown in Figure 4.1 */

#/* 



import cgkit.cri

from cgkit.cgtypes import *



# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



def Go():

    ShowQuads()



OFFSET = 1.2



def ShowQuads():

    RiRotate(-90.0, 1.0, 0.0, 0.0)

    

    RiTranslate(-OFFSET, 0.0, (OFFSET/2))

    RiSphere(0.5, -0.5, 0.5, 360.0, RI_NULL)        #/* Declare a sphere */

    

    RiTranslate(OFFSET, 0.0, 0.0)

    RiTranslate(0.0, 0.0, -0.5)

    RiCone(1.0, 0.5, 360.0, RI_NULL)                #/* Declare a cone */

    

    RiTranslate(0.0, 0.0, 0.5)

    RiTranslate(OFFSET, 0.0, 0.0)

    RiCylinder(0.5, -0.5, 0.5, 360.0, RI_NULL)      #/* Declare cylinder */

    

    RiTranslate(-(OFFSET*2), 0.0, -OFFSET)

    hyperpt1 =[ 0.4, -0.4, -0.4]

    hyperpt2 =[ 0.4,  0.4, 0.4]

    

    #/* Declare hyperboloid */

    RiHyperboloid(hyperpt1, hyperpt2, 360.0, RI_NULL)

    

    RiTranslate(OFFSET, 0.0, -0.5)

    RiParaboloid(0.5, 0.0, 0.9, 360.0, RI_NULL)     #/* Declare paraboloid */

    

    RiTranslate(OFFSET, 0.0, 0.5)

    RiTorus(.4, .15, 0.0, 360.0, 360.0, RI_NULL)    #/* Declare torus */





RiBegin (RI_NULL)  #/* Start Renderer */

RiDisplay("quadsmain.tiff", RI_FILE, "rgb", RI_NULL)

RiFormat( 512, 372, -1.0)

RiProjection (RI_PERSPECTIVE,RI_FOV,45)

RiTranslate (0.0, 0.0, 3.5)

RiWorldBegin ()

RiLightSource ("distantlight", RI_NULL)

RiAttributeBegin()



RiSurface ("plastic", Kd=1.0)

RiColor((0.97,0.64,0.39))

Go()

RiAttributeEnd()

RiWorldEnd()

RiEnd()

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• python cgkit
• 2010.11.23 Tuesday

「実践CGへの誘い」p.65
Listing 4.2

#list42.py

#/* Copyrighted Pixar 1989 */

#/* From the RenderMan Companion p. 65 */

#/* Listing 4.2   Using hyperboloids to create a surface of revolution */



import cgkit.cri

from cgkit.cgtypes import *



# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



NPOINTS=16



points = [

[1.5000,.0000],

[1.4600,.0900],

[1.3500,.1273],

[1.2625,.1203],

[1.1750,.1047],

[1.0875,.0935],

[1.0000,.0899],

[0.9375,.0982],

[0.8625,.1236],

[0.7250,.1851],

[0.5875,.2281],

[0.4500,.2383],

[0.3375,.2255],

[0.2250,.1953],

[0.0750,.1414],

[0.0000,.1125]

]



color = (1,0.26,0.15)



def Go():

    global color

    RiColor(color)

    RiSurface ("plastic", Kd=1.0)

    RiRotate(-90.0, 1.0, 0.0, 0.0)

    SurfOR(points, NPOINTS)





#/* Listing 4.2  Using hyperboloids to create a surface of revolution */



def SurfOR(points, npoints):

    #/*   

    # * For each adjacent pair of x,y points in the outline description, 

    # *  draw a hyperboloid by sweeping the line segment defined by  

    # *  those points about the z axis. 

    # */ 

    pp1 =[ points[0][1], 0, points[0][0]]

    for pt in range(1, npoints):

        pp2 =[ points[pt][1], 0, points[pt][0]]

        RiHyperboloid(pp1, pp2, 360.0, RI_NULL)

        tmp = pp1

        pp1 = pp2

        pp2 = tmp





RiBegin (RI_NULL)  #/* Start Renderer */

RiDisplay("list42.tif", RI_FILE, "rgb", RI_NULL)

RiFormat( 512, 372, -1.0)

RiProjection (RI_PERSPECTIVE,RI_FOV,45)

RiTranslate (0.0, -0.75, 2.2)

RiWorldBegin ()

RiLightSource ("distantlight", RI_NULL)

RiAttributeBegin()



Go()

RiAttributeEnd()

RiWorldEnd()

RiEnd()

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• python cgkit
• 2010.11.23 Tuesday

「実践CGへの誘い」p.67
Listing 4.3

#list43.py

#/* Copyrighted Pixar 1989 */

#/* From the RenderMan Companion p. 67 */

#/* Listing 4.3   Using RiTorus to create a wavelike pattern */



import cgkit.cri

from cgkit.cgtypes import *



# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



def TorusWave(nwaves, thetamax):

    if nwaves < 1:

        print "Need a positive number of waves\n"

    

    #/* Divide the net radius 1.0 among the waves and the hemisphere */

    innerrad = 2 / (8.0*nwaves + 2)

    RiRotate(90.0, 1.0, 0.0, 0.0)

    #/* Create the downward-opening hemisphere */

    RiSphere(innerrad, -innerrad, 0.0, thetamax, RI_NULL)

    

    outerrad = 0

    for wave in range(1,nwaves+1):

        #* Each iteration creates a downward-opening half-torus

        #*  and a larger upward-opening half-torus.

        outerrad = outerrad + (innerrad * 2)

        RiTorus(outerrad, innerrad, 0.0, 180.0, thetamax, RI_NULL)

        outerrad = outerrad + (innerrad * 2)

        RiTorus(outerrad, innerrad, 180.0, 360.0, thetamax, RI_NULL)



def Go():

    TorusWave(4, 250.0)





RiBegin (RI_NULL)  #/* Start Renderer */

RiDisplay("wavemain.tif", RI_FILE, "rgb", RI_NULL)

RiFormat( 512, 372, -1.0)

RiProjection ("perspective", RI_NULL)



RiWorldBegin ()

RiLightSource("ambientlight","intensity",0.4)

RiLightSource ("distantlight", RI_NULL)

RiAttributeBegin()

RiTranslate (-0.1, 0.0, 1.1)

RiRotate (50.0, -1.0, 1.0, 0.0)

RiColor((0.42,0.97,0.45))

RiSurface ("plastic", Kd=1.0)

Go()

RiAttributeEnd()

RiWorldEnd()

RiEnd()

RiProjection ("perspective", "fov", 45)
と書き換えてみた。

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• python cgkit
• 2010.11.23 Tuesday

Essential RenderManから、loop.cをPythonで試してみる。
Depth of field、PixelSamples、ShadingRateを調整しています。
ありがとうございます。

#/* loop.py - Create a line of Spheres */

# Essential RenderMan p.113

import cgkit.cri

from cgkit.cgtypes import *



# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



RiBegin(RI_NULL)

RiDisplay ("loop.tif",RI_FILE, RI_RGB)

RiFormat(320, 240,1)

RiPixelSamples( 8, 8)

RiShadingRate(0.25)

RiProjection (RI_PERSPECTIVE)

RiDepthOfField(2.8,0.100,2)

RiTranslate(0,0,0.25)

RiRotate(-10,0,1,0)

RiWorldBegin()

RiLightSource("ambientlight","intensity",0.2)

RiLightSource("distantlight", "from",[-1,1,-1])

RiTranslate(0.3,0,0)

for i in range(12):

    RiSurface ("plastic")

    RiColor((1.0,0.05,0.05))

    RiSphere(0.25,-0.25,0.25,360,RI_NULL)

    RiTranslate(-0.2,0,0.5)



RiWorldEnd()

RiEnd()

RiLightSource("distantlight", "from",[-4,1,-1])
ディスタントライトの方向を変更してみた。

#RiDepthOfField(2.8,0.1,2)
とコメントアウトすると、くっきりになる。
cgkitと3Delightを使用しました。

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• python cgkit
• 2010.11.23 Tuesday

Essential RenderManから、point.cをPythonで試してみる。
パーティクルも面白くなりそうです。
記述に関しては、cgkitのritest.pyが参考になります。
ありがとうございます。レンダリングは3Delightです。
以前書いた記事、CAPIでパーティクル

#point.py - Create a simple Particle System

import random, math

import cgkit.cri

from cgkit.cgtypes import *





# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())





COUNT = 1000



def jitter(scale):

    val=random.random()*1000

    return (val/500-1)*scale



position=[]

red=[1,0,0]

fov=30



#/*Generate Particle Postions*/

for i in range(COUNT):

    x=math.sin(i*0.5)*50+jitter(2)

    y=math.cos(i*0.1)*50+jitter(2)

    z=math.cos(i*0.5)*100+jitter(2)

    position.append(vec3(x, y, z))





RiBegin(RI_NULL)

RiDisplay ("point.tif","file","rgb",RI_NULL)

RiFormat(512, 384, -1.0)

RiPixelSamples( 4, 4)

RiShadingRate(0.5)

RiProjection ("perspective","fov",fov,RI_NULL)

RiWorldBegin()

RiTranslate(0,0,300)

RiColor(red)

RiPoints("P",position,RI_NULL)

RiWorldEnd()

RiEnd()

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• python cgkit
• 2010.11.24 Wednesday

イギリスのbournemouth大学のサイトを参考に作成してみた。
レンダリングは3Delightです。
勉強になります。ありがとうございます。

#point2.py - Create a simple Particle System

import random, math

import cgkit.cri

from cgkit.cgtypes import *

from random import uniform as ru





# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("3delight")

cgkit.cri.importRINames(ri, globals())



points=[]

width=[]

colour=[]

normals=[]

pappend=points.append

wappend=width.append

cappend=colour.append

nappend=normals.append



for i in range(0,1500):

    for ix in range(0,3):

        cappend(ru(0,1))

        pappend(ru(-2,2))

        nappend(ru(0,1))

    wappend(ru(0.01,0.2))

    



RiBegin(RI_NULL)

RiImager("background", "color background",(.2,.4,.6))

RiDisplay ("point2.tif","file","rgb",RI_NULL)

RiFormat(512, 384, -1.0)

RiPixelSamples( 4, 4)

RiShadingRate(1)

RiProjection ("perspective","fov",30,RI_NULL)

RiWorldBegin()

RiLightSource("ambientlight","intensity",0.4)

RiLightSource("distantlight", "from",[0,0,1])

RiTranslate(0,0,6)

RiSurface("plastic")

RiPoints("P",points,"Cs",colour,"width",width,"N",normals,RI_NULL)

RiWorldEnd()

RiEnd()

実は、3DelightのPointsは、法線N部分(,"N",normals)が無視されるようだ。図のようにdiskはカメラ方向を見ている。Prmanではdiskの面がいろいろ変わってくる。次の記事を参照してください。

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• python cgkit
• 2010.11.26 Friday

cgkitとPrmanを組み合わせる。どうも3Delightとprmanでは、RiPointの仕様がちがうようです。
3Delightのマニュアルはこちらになりますが、blobbyが使えて、遊べそうです。

さてさてPrmanだと以下の通りになります。

#point2.py - Create a simple Particle System

import random, math

import cgkit.cri

from cgkit.cgtypes import *

from random import uniform as ru





# Load the RenderMan API.

# Replace the library name with whatever renderer you want to use.

ri = cgkit.cri.loadRI("C:\Program Files (x86)\Pixar\RenderManProServer-14.4\lib\libprman")

cgkit.cri.importRINames(ri, globals())



points=[]

width=[]

colour=[]

normals=[]

pappend=points.append

wappend=width.append

cappend=colour.append

nappend=normals.append



for i in range(0,1500):

    for ix in range(0,3):

        cappend(ru(0,1))

        pappend(ru(-2,2))

        nappend(ru(0,1))

    wappend(ru(0.01,0.2))

    



RiBegin(RI_NULL)

RiImager("background", "color background",(.2,.4,.6))

RiDisplay ("point2_pr.tif","file","rgb",RI_NULL)

RiFormat(512, 384, -1.0)

RiPixelSamples( 4, 4)

RiShadingRate(1)

RiProjection ("perspective","fov",30,RI_NULL)

RiWorldBegin()

RiLightSource("ambientlight","intensity",0.4)

RiLightSource("distantlight", "from",[0,0,1])

RiTranslate(0,0,6)

RiSurface("plastic")

RiPoints("P",points,"Cs",colour,"width",width,"N",normals,RI_NULL)

RiWorldEnd()

RiEnd()

実行方法は、

>point2_pr.py |prman


ありがとうございます。調べて納得して、繰り返し繰り返しですね。

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