Python

Accessing current camera

Here is an example how we can get the current camera data and manipulate them through python

I use this script to set the nearclip plane values to quickly hide the geos in viewport. Will be very usefull when you want to toggle hide/unhide quickly while matching to something to a backplate 

import hou,toolutils

viewer    = toolutils.sceneViewer()

viewport  = viewer.curViewport()

camera    = hou.GeometryViewport.camera(viewport)

near = camera.parm("near")

if near.eval()==0.0088:

    near.set(999999)

else:

    near.set(0.0088)

print "nearclip of camera %s set to %s"%(camera.name(),near.eval())

Get print all uniuqe attributes

# example to print all unique materials

node = hou.selectedNodes()[0]

shop_path = node.geometry().findPrimAttrib("shop_materialpath")

if shop_path :

    for path in shop_path.strings() :

        print path

To Reload a module in Houdini without closing the session

#using the reload() method of importlib module

import movfxTools

import importlib 

importlib.reload(movfxTools)

Arnold light from Mantra light

Extracts exposure,intensity and sizes of mantra area lights and create arnold light of same values

import hou

node = hou.selectedNodes()[0];

int = node.parm('light_intensity').eval()

exp = node.parm('light_exposure').eval()

asX = node.parm('areasize1').eval()

asY = node.parm('areasize2').eval()

posx = node.position()[0]

posy = node.position()[1] - 1

pos = [posx,posy]

print pos

context = node.parent()

arLight = context.createNode('arnold_light')

arLight.setInput(0, node)

arLight.setPosition(pos)

arLight.parm('ar_light_type').set(3)

arLight.parm('ar_intensity').set(int)

arLight.parm('ar_exposure').set(exp)

arLight.parm('ar_quad_sizex').set(asX)

arLight.parm('ar_quad_sizey').set(asY)

print arLight

Align Nodes

"A" is the shortcut to quickly align nodes, But it distributes the nodes evenly , we cant align in one axis without modifying the positions in other axis 

So I wrote this simple code for my shelf to do that.

import hou

def alignHorizontal():

    nodes = hou.selectedNodes()

    posYs = [node.position().y() for node in nodes]

    avgPosY = 0.0

    for posY in posYs:

        avgPosY += posY

    avgPosY = avgPosY/len(posYs)    

    for node in nodes:

        x = node.position().x()

        node.setPosition([x,avgPosY])

alignHorizontal()

import hou

def alignVertical():

    nodes = hou.selectedNodes()

    posXs = [node.position().x() for node in nodes]

    avgPosX = 0.0

    for posX in posXs:

        avgPosX += posX

    avgPosX = avgPosX/len(posXs) 

    for node in nodes:

        y = node.position().y()

        node.setPosition([avgPosX,y])

alignVertical()

Netbox with padding

####netbox with padding - by mohanpugaz on sidefx forum

import hou

### net box with padding

### set your padding here

padX = 2

padY = 2

##

##init vars

nodes = hou.selectedNodes()

parent = nodes[0].parent()

pad = (padX,padY)

posx = []

posy = []

curpos = 0

## run a loop to get all nodes x and y position

for n in nodes:

    curpos = 0

    curpos = n.position()

    posx.append(curpos[0])

    posy.append(curpos[1])

## extract the min and max postion from the position lists and arrange it in a sequence(see help on boundingRectangle.setTo)

maxpos = (max(posx),max(posy))

minpos = (min(posx),min(posy))

seq = (minpos[0],minpos[1],maxpos[0],maxpos[1])

## create a new bounding rectangle and set our min and max values

bound = hou.BoundingRect()

bound.setTo(seq)

## expand the bound 

bound.expand(pad)

## create a netbox and set our expanded bound value

box = parent.createNetworkBox()

box.setBounds(bound)

Viewer Screen capture shelf tool

from time import gmtime, strftime

# GET VIEWPORT CAMERA PATH

cur_desktop = hou.ui.curDesktop()

desktop = cur_desktop.name()

panetab = cur_desktop.paneTabOfType(hou.paneTabType.SceneViewer).name()

persp = cur_desktop.paneTabOfType(hou.paneTabType.SceneViewer).curViewport().name()

camera_path = desktop + "." + panetab + "." + "world" + "." + persp

# BUILD DEFAULT FILE NAME FROM CURRENT TIME

default_filename = strftime("screenshot_%d_%b_%Y_%H_%M_%S.jpg", gmtime())

# SELECT FILE

#filename = hou.ui.selectFile( title='Select Screenshot File', default_value=default_filename, file_type=hou.fileType.Image )

filename = "ip"

# WRITE TO FILE

if filename is not None:

    frame = hou.frame()

    hou.hscript( "viewwrite -f %d %d %s '%s'" % (frame, frame, camera_path, filename) )

RND for HoudiiniCollectFiles(WIP!!!!!!)

import os

def findFileInputs(node):

    """this function takes the given node object and return list of  

    parameters which are file references"""

    parms = node.parms()

    fileParms = []

    for parm in parms:  

        if parm.parmTemplate().type().name() == "String":

            if parm.parmTemplate().stringType().name() == "FileReference":

                fileParms.append(parm)

    return fileParms

def findKids(node):

    nodeList = []

    def kids(node):

        for kid in node.children():

            nodeList.append(kid)

            kids(kid)

        return nodeList

    nodeList = kids(node)

    return nodeList

root = hou.node("/")

files = []

nodeFiles = []

paths = []

for kid in findKids(root):

    nodeFiles=findFileInputs(kid)

    files+=nodeFiles

for afile in files:

    paths.append(afile.eval())

paths = filter(None, paths)

for path in paths:

    print path

For activating node inside an asset (for example paint node here)

#1 callback script for the button

hou.pwd().hdaModule().functionName(kwargs)

#2 In the asset edit > in python module

def functionName(scriptargs):

    sopnode = scriptargs['node']

    viewer = toolutils.sceneViewer()

    paint = sopnode.node("paint_node_name_here")

    paint.setCurrent(True, True)

    viewer.enterCurrentNodeState()

Parameter init

__init__(name, label, num_components, default_value=(), min=0.0, max=10.0, min_is_strict=False, max_is_strict=False, look=hou.parmLook.Regular, naming_scheme=hou.parmNamingScheme.XYZW, disable_when=None, is_hidden=False, is_label_hidden=False, join_with_next=False, help=None, script_callback=None, script_callback_language=hou.scriptLanguage.Hscript, tags={}, default_expression=(), default_expression_language=())

Most usefull commands:

hou.ui.displayMessage("string")

hou.expressionGlobals() - for setting custom function to work on parameter expression

hou.parm('/obj/geo1/file1/reload').pressButton()

Useful Links:

To start learnig from basic houdini python

http://www.sidefx.com/docs/houdini/hom/intro

Script Locations

http://www.sidefx.com/docs/houdini/hom/locations

Startup Tuts

http://www.warshaw.co.uk/links/pythonh.html

Adding Menus

http://houdinitricks.tumblr.com/