numpy question.

[saelly]

node = hou.pwd()

geo = hou.pwd().geometry()

 

for p in geo.points():

    npole = hou.Vector3(node.parmTuple('north_pole').eval())

 

    pos = hou.Vector3(p.position())

 

    print pos - npole

 

 

============================================================

 

"pos - npole" (vector subtraction)

 

To replace this code with a "numpy", what should I do? (no for loop)

 

help me plz..

Edited April 6, 2014 by saelly

[ali]

import numpy

 

node = hou.pwd()

geo = node.geometry()

 

# Add code to modify contents of geo.

# Use drop down menu to select examples.

 

 

#get array of all points attr "P" as string buffer...

string_buffer = geo.pointFloatAttribValuesAsString("P", float_type=hou.numericData.Float32)

 

#create numpy array from our string buffer...

array_of_pos = numpy.fromstring(string_buffer, dtype='float32' ).reshape(-1, 3)  # and reshape to make it 2dimentional (array of vectors)

 

# doing something with your array... (google the numpy broadcast rules)

array_of_pos -= (20, 4, 2) #per-element operation

 

#and then you need to copy your numpy array back to points attr "P"

geo.setPointFloatAttribValuesFromString("P", numpy.getbuffer(array_of_pos), float_type=hou.numericData.Float32)

 

# WORKED (h13)!

Edited April 6, 2014 by ali

[saelly]

 

import numpy

 

node = hou.pwd()

geo = node.geometry()

 

# Add code to modify contents of geo.

# Use drop down menu to select examples.

 

 

#get array of all points attr "P" as string buffer...

string_buffer = geo.pointFloatAttribValuesAsString("P", float_type=hou.numericData.Float32)

 

#create numpy array from our string buffer...

array_of_pos = numpy.fromstring(string_buffer, dtype='float32' ).reshape(-1, 3)  # and reshape to make it 2dimentional (array of vectors)

 

# doing something with your array... (google the numpy broadcast rules)

array_of_pos -= (20, 4, 2) #per-element operation

 

#and then you need to copy your numpy array back to points attr "P"

geo.setPointFloatAttribValuesFromString("P", numpy.getbuffer(array_of_pos), float_type=hou.numericData.Float32)

 

# WORKED (h13)!

 

 

Thank you peon!!!

 

thanks a lot~^^

Have a nice day~!!!

[freaq]

what is your reason of moving to numpy btw? 

does it deliver better performance? or operations not available in Houdini?

[saelly]

what is your reason of moving to numpy btw? 

does it deliver better performance? or operations not available in Houdini?

 

numpy module is high performance