A place to share my what I've been up too in my life...
To run a python script on a houdini hip file from the cmd line without opening at GUI version of houdini use the syntax below:
/opt/hfs18.5/bin/hython <YOUR_HIP_FILE> <YOUR_PY_SCRIPT>
Haven't yet checked about passing args to the py script but will edit and update with that later.
Below is what I've found about being able to add custom menus and importing scripts into Houdini (for use on shelf buttons etc).
The houdini.env file is exactly like Maya's maya.env file. You'll find in:
$HOME/houdini18.5/houdini.env
aka
~/houdini18.5/houdini.env
The official documentation about this is here
Super simple. Just add the path(s) to where your code modules are to the PYTHONPATH env var in the houdini.env file. Separate each path with : or ; (both should work although : is more linux-y)
eg:
PYTHONPATH=/path/to/my/custom/scripts:/other/path/to/scripts
The official documentation about this is here
This is more fiddly. The official documentation about this is here
Firstly you need to set the HOUDINI_MENU_PATH in your houdini.env to point at where your menu's are, and you must make sure to use the :& after you put the path in, otherwise it will only load the menu that you've created there. See the examples below:
This will only load the menu's you've set in that path
HOUDINI_MENU_PATH=$HOME/path/to/menus
This will effectivly append your menu to the default set of menus
HOUDINI_MENU_PATH=$HOME/path/to/menus:&
Nb: if you do this:
HOUDINI_MENU_PATH=&:$HOME/path/to/menus
Then your menu will be inserted before any other menus (so i'll appear on the left-most side of the menu bar, before the "File" menu.
Menu files are xml files that have to have specific names, and syntax that's detailed in the documentation linked above.
# Houdini python reference: # https://www.sidefx.com/docs/houdini/hom/index.html # hou is the name of the python houdini commands. # It's already imported in a python shell that's loaded from Houdini #### FILE OPERATIONS #### # open a file file_name = "/my/file/path.hip" hou.hipFile.load(file_name) # save a file hou.hipFile.save(file_name) #### WORKING WITH NODES #### # GETTING/SELECTING path_to_node = "/obj/geo1" node = hou.node(path_to_node) # set a node to be selected in the GUI new_geo_node.setSelected(True) # TYPES # getting a node's type (this get's a NodeType class) node_type = node.type() node_type_name = note_type.name() print node_type_name >>> "geo" # PARAMETERS # setting parameters on a node #(NB: this works much the same way that Nuke does it's knobs with python) parameter_name = "tx" # first get the parameter parameter = node.parm(parameter_name) value = 2 # then set the value you want. parameter.set(value) # SET FLAGS ON NODES # Some settings on nodes are known as flags (not sure what the technical difference # is yet between parameters and flags) # Some notable flags display and selectable in viewport can be modified as shown below # set the display of the geo to off new_geo_node.setDisplayFlag(False) # set the select-ablity of the geo to off new_geo_node.setSelectableInViewport(False) # set the lock state of the node new_geo_node.setHardLocked(True) # MULTIPLE NODES # There's almost certainly a better way of doing this, but a basic # way to list nodes in a scene looks like this: # get the root root = hou.node("/") # get the children of that node # (which are the different houdini contexts (eg: obj, mat, cop, chop, etc) contexts = root.children() # for each context for cxt in contexts: print cxt.name() # get the children of that context nodes = cxt.children() if nodes: # for each node in that context print the name of the node for n in nodes: print n.name() #### CREATING NEW NODES #### # to create new nodes you've got to do so from and class instance of the context in # which that node can be created. # eg: for a Geometry node you need create it from an instance of the "/obj" context # eg: for a Shader node (principledShader) you need to create it from an instance of # the "/mat" context # setup the instance of the obj context obj_context = hou.node("/obj") new_node_type = "geo" new_node_name = "my_geo" # create the geometry container (essentially the transform node to use Maya terms) new_geo_node = obj_context.createNode(new_node_type, new_node_name) primitive_type = "box" primitive_name = "my_geo_box" # now create the primitive inside the geo container (ie the shape node in Maya terms) box = new_geo_node.createNode(primitive_type, primitive_name) #### NODE CONNECTIONS AND INPUTS #### # setting the input of one node to the output of another # create a new polybevel node so we've got something to connect up polybevel = new_geo_node.createNode("polybevel") # set the 1st input to the box created above. # NB: The first arg is the index of the input 'slot' # The second arg must be a class object. A string to the path of the object is not sufficient polybevel.setInput(0, box) # break/disconnect inputs # the way to do this is to just set a None input. polybevel.setInput(0, None) #### MISC #### # POSITIONING NODES IN THE GRAPH # get the current position of the node in the graph. # This appears as a list but is actually and instance of the hou.Vector2 class. current_position = new_geo_node.position() >>> [-1,1] # set the position of a node in the graph by passing a list with the x and y position # you want to node to go to. new_geo_node.setPosition([0,2])
