Direct 10 ch06 Lighting

  Let there be light.

 

介绍了光与物体之间的作用,主要是pixel与颜色之间的关系.

其中提到了cos公式,为了做本章的图,我用python产生数据,gnuplot队数据进行展现.

python 代码:

import math
import io

output = io.open("LightsData.txt",'w');

thetaStart = -2*math.pi
thetaEnd   =  2*math.pi
thetaCount =  10000
deltaTheta =  (thetaEnd-thetaStart)/thetaCount
iRange = range(1,thetaCount,1)

theta  = thetaStart

for i in range(1,thetaCount,1):
    result  = math.sin(theta)
    if (result < 0):
        result = 0
        
    result8 = result**8
    if (result8 <0 ):
        result8 = 0
        
    result128 = result**128
    if (result128 < 0):
        result128 = 0
        
    output.write(u'%f  %f  %f  %f\n' %(theta, result, result8, result128))
    theta = theta + deltaTheta

    
output.close()

 

 

 

图例: