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Writing file with particle data

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ThomasSchwenke
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Joined: Nov. 2016
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Hi,

I want to create a file that is filled with particle positions. Something like that:
1,2,3
3,2,1
2,2,0

These would be the x,y,z positions of particles.

Can I do this kind of stuff with a filedata node? Or a file node in conjunction with a vex node? Or do I need to use Python for this kind of task?

Best wishes,
Thomas
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Enivob
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Joined: June 2008
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AFAIK Vex can't write to a file. So Python might be the way to go.
The File node can write to several modern and legacy formats, is there a reason why you are inventing a new format?

Here is a small snippet of the default sphere written out to .RIB format. Maybe you could just cut and paste data from a RIB file into your own format..?
    "P" [ -2.111098e-08 0.5 -5.656685e-09 3.646268e-08 -0.5 9.770174e-09
	 0.1294095 0.4829629 0 0.125 0.4829629 -0.03349365
	 0.1120719 0.4829629 -0.06470477 0.09150636 0.4829629 -0.09150636
	 0.06470476 0.4829629 -0.112072 0.03349366 0.4829629 -0.125
	 9.770148e-09 0.4829629 -0.1294095 -0.03349364 0.4829629 -0.125
	 -0.06470475 0.4829629 -0.112072 -0.09150634 0.4829629 -0.09150638
	 -0.1120719 0.4829629 -0.0647048 -0.125 0.4829629 -0.03349369
	 -0.1294095 0.4829629 -5.039393e-08 -0.125 0.4829629 0.0334936
	 -0.112072 0.4829629 0.06470472 -0.09150641 0.4829629 0.09150631
	 -0.06470481 0.4829629 0.1120719 -0.0334937 0.4829629 0.125
	 -6.016408e-08 0.4829629 0.1294095 0.03349359 0.4829629 0.125
	 0.0647047 0.4829629 0.112072 0.0915063 0.4829629 0.09150642
	 0.1120719 0.4829629 0.06470484 0.125 0.4829629 0.03349375
	 0.25 0.4330127 0 0.2414814 0.4330127 -0.06470475
	 0.2165063 0.4330127 -0.125 0.1767767 0.4330127 -0.1767767
	 0.125 0.4330127 -0.2165063 0.06470476 0.4330127 -0.2414814
	 1.887447e-08 0.4330127 -0.25 -0.06470472 0.4330127 -0.2414815
Edited by Enivob - Dec. 14, 2016 13:08:29
Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.
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ThomasSchwenke
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Joined: Nov. 2016
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Hi,

Thx for your response. A Python node attached to the import_source node does the trick. The specification is according to Otoys scatter node: https://docs.otoy.com/#standalone-v3-geometry-the-scatter-node [docs.otoy.com]

Source code below…

node = hou.pwd()
geo = node.geometry()
# save scatter csv file
# create or replace file
csvfile = open("I:/test/scatter"+str(hou.intFrame())+".csv","w")
# iterate through points and
# save positions for each point
for point in geo.points():
    pos = point.position()
    # pos x
    csvfile.write("1 0 0 ")
    csvfile.write(str(pos[0]))
    # pos y
    csvfile.write(" 0 1 0 ")
    csvfile.write(str(pos[1]))
    # pos z
    csvfile.write(" 0 0 1 ")
    csvfile.write(str(pos[2]))
    # start new line
    csvfile.write("\n")
    
# close file
csvfile.close()

Best wishes,
Thomas
Edited by ThomasSchwenke - Dec. 15, 2016 08:34:38
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