Thread: Re: [Visualpython-users] 3d surface plot animation

Here is a small section of the original faces_heightfield example:

class Model:
    def __init__(self):
        self.frame = frame()
        self.model = faces(frame=self.frame, color=color.cyan)
        self.vertices = []

    def FacetedTriangle(self, v1, v2, v3, color=color.white):
        """Add a triangle to the model"""
        for v in (v1,v2,v3):
            self.vertices.append(v)

I cannot see why the color=color.white is there - it seems to have no
effect!? Replacing white with red doesn't change anything.
Rather, I would like to input something like c1,c2,c3 (three colors for
the vertices) in the FacetedTriangle. But how exactly?

I regret that I'm such a poor programmer but it could be a great help if
someone would implement this change in faces_heightfield.

Poul Riis

A little timetesting indicates that not the calculation of z-values but
the drawing takes time....

Poul Riis

 

Poul wrote...

> Yes, I know, but even the original example 'faces_heightfield' is 

> too complicated for me to see how I can add these colors. Can 

> someone give me just a little hint?

 

 

Below is some added color.  Search for “s.dube”

 

-Shawn Dube

 

 

 

from visual import *

from time import *

 

class Model:

   def __init__(self):

       self.frame = frame()

       self.model = faces(frame=self.frame, color=color.blue)

       self.vertices = []

 

   def FacetedTriangle(self, v1, v2, v3, color=color.red):

       """Add a triangle to the model"""

       for v in (v1,v2,v3):

           self.vertices.append(v)

 

   def FacetedPolygon(self, *v):

       """Appends a planar polygon of any number of vertices to the model"""

       for t in range(len(v)-2):

           self.FacetedTriangle( v[0], v[t+1], v[t+2] )

           self.FacetedTriangle( v[0], v[t+2], v[t+1] )

 

   def DrawNormals(self, scale):

       pos = self.model.pos

       normal = self.model.normal

       for i in range(len(pos)):

           arrow(pos=pos[i], axis=normal[i]*scale)

 

# function added by s.dube

def PosArrayToHueColorArray( aPos, index ):

   # aPos is an array of positions

   # index chooses from which axis (x,y,z) to base color

   aPos= aPos.copy()

   v= hsplit(aPos,3)[index]

   v -= v.min()

   v *= 5.0 / v.max()

   # red

   r= v+1.0

   r %= 6.0

   r -= 3.0

   r= abs(r)

   r -= 1.0

   r= r.clip(0.0,1.0)

   # green

   g = v+3.0

   g %= 6.0

   g -= 3.0

   g= abs(g)

   g -= 1.0

   g= g.clip(0.0,1.0)

   # blue

   b= v

   b += 5.0

   b %= 6.0

   b -= 3.0

   b= abs(b)

   b -= 1.0

   b= b.clip(0.0,1.0)

   # wrap-up

   return hstack((r,g,b))

 

 

class Mesh (Model):

   def __init__(self, xvalues, yvalues, zvalues):

       global g

       Model.__init__(self)

 

       points = zeros( xvalues.shape + (3,), float )

       points[...,0] = xvalues

       points[...,1] = yvalues

       points[...,2] = zvalues

 

       for i in range(zvalues.shape[0]-1):

           for j in range(zvalues.shape[1]-1):

               self.FacetedPolygon( points[i,j], points[i,j+1],

                                    points[i+1,j+1], points[i+1,j] )

               

       self.model.pos = self.vertices

       self.model.color= PosArrayToHueColorArray( self.model.pos, 1 ) # added by s.dube

       self.model.make_normals()

       self.model.smooth()

       self.model.make_twosided()

       

dxy=0.02 # Length of x-y-intervals

x = arange(-1,1+dxy,dxy)

y = arange(-1,1+dxy,dxy)

d=0.8 # Distance between two oscillators

dh=d/2 # Half that distance

lambdah=d/5 # Wavelength

k=2*pi/lambdah

T=10 # Oscillator period

A=0.025 # Oscillator amplitude

omega=2*pi/T

m1=12 #Number of wavelengths from oscillator 1 to point of constructive interference

m2=10 #Number of wavelengths from oscillator 2 to point of constructive interference

n=m1-m2

m=m2

xci=n*(n+2*m)*lambdah**2/2/d

yci=sqrt((d**2-(n*lambdah)**2)*(((n+2*m)*lambdah)**2-d**2))/2/d

print('Point of constructive interference: (',xci,yci,')')

print(sqrt((xci-dh)**2+yci**2)/lambdah)

print(sqrt((xci+dh)**2+yci**2)/lambdah)

N1=m*20

N2=(m+n)*20

a1points=[]

a2points=[]

for i in range(0,N1+1):

   a1points.append((i*(xci-dh)/N1+dh,2*A*cos(i/N1*m*2*pi),1-i*yci/N1))

for i in range(0,N2+1):

   a2points.append((i*(xci+dh)/N2-dh,2*A*cos(i/N2*(m+n)*2*pi),1-i*yci/N2))

def f(x,y,t):

   return A*(sin(k*sqrt((x-dh)*(x-dh)+y*y)-omega*t)+sin(k*sqrt((x+dh)*(x+dh)+y*y)-omega*t))

 

source1=sphere(radius=0.02,pos=(dh,0,1),color=color.yellow)

source2=sphere(radius=0.02,pos=(-dh,0,1),color=color.red)

z = zeros( (len(x),len(y)), float )

x,y = x[:,None]+z, y+z

 

curve(pos=a1points,color=color.red)

curve(pos=a2points,color=color.yellow)

 

Ncp=20

ncmax=floor(d/lambdah)

if ncmax*lambdah==d:

   ncmax=ncmax-1

for nc in range(1,ncmax+1):

   bhyp=sqrt(-(nc*lambdah/2)**2+(d/2)**2)

   ahyp=bhyp*nc/sqrt(-nc*nc+(d/lambdah)**2)

   print('ahyp,bhyp:',ahyp,bhyp)

   txmax=acosh(1/ahyp)

   tymax=acosh(2/bhyp)

   tmax=txmax

   if tymax<txmax:

       tmax=tymax

   hyppoints=[]

   for i in range(0,Ncp+1):

       t=i*tmax/Ncp

       hyppoints.append((ahyp*cosh(t),2*A,-bhyp*sinh(t)+1))

   curve(pos=hyppoints,color=color.green)

   hyppoints=[]

   for i in range(0,Ncp+1):

       t=i*tmax/Ncp

       hyppoints.append((-ahyp*cosh(t),2*A,-bhyp*sinh(t)+1))

   curve(pos=hyppoints,color=color.green)

   hyppoints=[]

   hyppoints.append((0,2*A,-1))

   hyppoints.append((0,2*A,1))

   curve(pos=hyppoints,color=color.green)

for i in range(0,100):

   surface=Mesh( x, f(x,y-1,i) , y )

   #sleep(0.01)

   surface.model.visible=False

   del surface

   source1.pos=(-dh,-A*sin(omega*i),1)

   source2.pos=(dh,-A*sin(omega*i),1)

i=100

surface=Mesh( x, f(x,y-1,i) , y )

 

 

You're right, that 4th argument for FacetedTriangle isn't used and can
be deleted. Or, if you want to call FacetedTriangle with both vertex
locations and color specfications, you could revise the routine like
this:

def FacetedTriangle(self, v1, v2, v3, c1, c2, c3):
    self.vertices.append(pos=v1, color=c1)
    self.vertices.append(pos=v2, color=c2)
    self.vertices.append(pos=v3, color=c3)

Then you would say self.FacetedTriangle(v1, v2, v3, c1, c2, c3).

Bruce Sherwood

On Fri, Oct 14, 2011 at 3:07 PM, Poul Riis <Pou...@sk...> wrote:
>
> Here is a small section of the original faces_heightfield example:
> class Model:
>    def __init__(self):
>        self.frame = frame()
>        self.model = faces(frame=self.frame, color=color.cyan)
>        self.vertices = []
>    def FacetedTriangle(self, v1, v2, v3, color=color.white):
>        """Add a triangle to the model"""
>        for v in (v1,v2,v3):
>            self.vertices.append(v)
> I cannot see why the color=color.white is there - it seems to have no
> effect!? Replacing white with red doesn't change anything.
> Rather, I would like to input something like c1,c2,c3 (three colors for the
> vertices) in the FacetedTriangle. But how exactly?
> I regret that I'm such a poor programmer but it could be a great help if
> someone would implement this change in faces_heightfield.
> Poul Riis