I have a script that includes 2 functions to calculate distance between points. One is called euclid_d() and the other one is called manhattan_d()

At the moment, when I want to switch between the 2 functions I have to dive into the code, exchange the functions, and then run the script. How could I do that from the python SOP interface? Perhaps a drop-down menu? How is it done?

Just create a drop down menu and then use an if/else statement.


calc_type = hou.pwd().evalParm(“calculate”)
if calc_type == “euclid”:
euclid_d()
elif calc_type == “manhattan”:
manhattan_d()


Where euclid and manhattan are values of a drop down menu.

Cool. That works.

But now I keep getting this warning again, every time I do something. Is there a way to switch it of, permanently?

LOL. A litle offtopic.
In meantime when I downloaded this topic I also started Houdini, then maximized browser again and your image with warning showed, my reaction = WTF ? then I presed X to close this window and realized that its your post .

You have somehow changed your parameter layout, through either the Edit Parameter Interface or through scripting. This causes this warning when you then try and modify your asset through the Type Properties.

graham
You have somehow changed your parameter layout, through either the Edit Parameter Interface or through scripting. This causes this warning when you then try and modify your asset through the Type Properties.

Yes, I made the drop down menu. But I don't want this message to pop up everytime I run my Python code…

Well if you are using the Operator Type Properties window and you hit Apply/Accept and there are parameter layout changes that have happened that aren't due to changes in the Type Properties then you will always get that dialog.

I have several parameters that I read in from the parameter layout but when I enter new values the Python SOP doesn't cook unless I open type properties and accept.

How I can force the SOP to cook when I update any parameters, or at least have a button that's easy to get at?

What kind of parameter values are you changing? The simple act of changing any parameter should be causing the operator to cook again. I'm pretty sure I've never had a problem like you are describing. Without seeing the operator I'm afraid I can't offer much in the way of suggestions.

If you want to force a node to cook you can bypass/unbypass it, or you could add a button that calls hou.pwd().cook()

I wanted to send you the otl, but for some reason it doesn't save the added parameters. (two floats, a and b, and a string).

What this does is: scale an attribute from a bottom value a to a top value b. A bit like the fit expression except that it gets the original max and min values automatically. The attribute name is supplied by a parameter.

Now, if I change the parameter, say the value a, then it doesn't recook.



# This code is called when instances of this SOP cook.
geo = hou.pwd().geometry()
points = geo.points()
# Add code to modify the contents of geo.

att_name = hou.pwd().evalParm(“att_parm”)
a = hou.pwd().evalParm(“a_parm”)
b = hou.pwd().evalParm(“b_parm”)
print “Attribute”,att_name,“from a”,a,“ to b,”,b
attl = geo.findPointAttrib(att_name)
lst =


def read_att(attl):
for p in points:
pn = p.number()
lst.append(p.attribValue(attl))
return lst

#—————————————————-
def normList(lst, lower, upper):
print lower,upper
r = float(upper - lower) #the length of the interval
lstr = float(max(lst) - min(lst)) #the “length” of the list
lst = #make the list have the same “length” as the interval

diff = lower - min(lst) #calculate how “off” the list is
lst = #correct it
return lst
#—————————————-
def write_att(lst):
for p in points:
i = p.number()
value = normalized
p.setAttribValue(attl,value)

#****************RUN CODE*****************

lst = read_att(attl)
normalized = normList( lst, a, b)
write_att(normalized)

Soothsayer
I wanted to send you the otl, but for some reason it doesn't save the added parameters. (two floats, a and b, and a string).

This is your problem and what I tried to say earlier. You added those parameters using the Edit Parameter Interface window as opposed to the Operator Type Properties. These parameters are spare parameters, not parameters belonging to the actual asset definition. This is why you receive the dialog when you hit Accept/Apply in the Type Properties. It wants to know what to do with your spare parameters. Spare parameter changes don't trigger recooking of the node.

To fix it all you want to remove the spare parameters, which you can do through the gear menu Edit Parameter Interface window, or by RMB on the labels of those parameters and choosing More>Delete Spare Parameter option. If you then add them back using the Operator Type Properties window for the asset all should be fine.

oooooooooooooh, now I get it! Thanks!

Also, take a look at hou.Geometry.pointFloatAttribValues(). You can use it to replace your read/write att functions. pointFloatAttribValues() returns the attribute values for all the points in order into a single tuple without you having to iterate the points and append the value. It is significantly faster, especially when dealing with lots of points. Same goes with setPointFloatAttribValues().

Time for another basic python question. :wink:

I have the numpy module with my normal standard IDLE python and I'd like to import it inside Houdini pyhton. I tried putting the folder into houdini\scripts\python but that didn't work. (Maybe there is some stuff missing because numpy installs with an exe, so I'm not sure what kind of files it puts where)

So, how do I do that, on windows xp?

I am trying to create points from a script running from the shelf but I get the message 'ObjNode' object has no attribute ‘createPoint’



obj = hou.node(“/obj”)
obj.createNode(“geo”, “mypoints” , run_init_scripts=False)
geo = hou.node(“/obj/mypoints”)

dpoints={0:}
x = dpoints
y = dpoints
z = dpoints
point = geo.createPoint()
point.setPosition((x, y, z))

I think it's got something to do with not referring correctly to the innards of the node, but I'm not sure how to get it working. If it was in a SOP I'd use pwd(), but I am outside of it.

You are trying to add points to an object node which doesn't make sense. You can only add points using HOM inside the cooking code of a Python SOP. If you want to generate points from a shelf tool you should create an Add SOP inside your geo container and plug your positions into the parms.

So, how do I create an add sop via python?

I tried the code in a custom operator python sop and it works fine there. It's just that I then have to go and create a node and append my operator wheras invoking all this from a shelf-run tool would be more convenient.

To do it with an Add Sop you could do something like this:
dpoints={0:}

obj = hou.node(“/obj”)
container = obj.createNode(“geo”, “mypoints” , run_init_scripts=False)

add = container.createNode(“add”)
add.parm(“usept0”).set(1)
add.parmTuple(“pt0”).set(dpoints)

Thanks Graham! You put me on the right track there.

For the record, if anybody needs to do something similar for a big dictionary containing points, this is how I did it:

import cPickle as pickle
pfile = file(“C:\points.txt”)
dpoints = pickle.load(pfile)
s=“”

for i in dpoints.keys():
pt = dpoints
pt = str(pt)
pt = pt.replace(“[”,“”)
pt = pt.replace(“]”,“ ”)
s = s+pt

obj = hou.node(“/obj”)
container = obj.createNode(“geo”, “mypoints” , run_init_scripts=False)
add = container.createNode(“curve”)
add.parm(“coords”).set(s)

Is it possible to create parameters dynamically?

Something like a createParameter() method?