Canada - Part 1

ON-60 Algonquin Provincial Park

Freshmart in Eganville

Algonquin Arts Centre Telephone Booth

Sunset

Mont Tremblant

Downtown Toronto

 

Travelling trio

Learning Houdini - part 3 - Running from terminal

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.

Learning Houdini - Part 2 - Adding Menu's and importing modules

Below is what I've found about being able to add custom menus and importing scripts into Houdini (for use on shelf buttons etc). 

Setting up the houdini.env file 

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

Adding python modules

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

Adding custom menus

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.

Learning Houdini - Part 1

Started learning Houdini properly this weekend. Some notes below on various discoveries.

5 Hour free course on Houdini basics: 

https://www.hipflask.how/products/houdini-made-easy-01-the-core-essentials 

Shout out to Denis J-F for putting me onto this one. So far so good. Well explained and has playback speed controls which is always a godsend when watching tutorials so you can fast-forward on the real basic stuff that's easy to digest and then slow down again for the bits that need a bit more concentration.

Key things to remember:

Houdini is like a UNIX style OS. 

Nodes organised like folders and are the address to themselves within the DCC

eg "/" is the root of a houdini file

"/obj/geo1" is the 'path' to the node "geo1"

Houdini Python Cheatsheet:

(Formatting generated with http://hilite.me/ using the "fruity" style)

# 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])

Costa Rica - Part 2

Costa Rica - Part 1

This is the first round of photo's from Costa Rica. More to follow.

Cahuita National Park

Blue-Crowned Motmot

Manzanillo

Jesus Christ Basilisk

Arenal Volcano & Monte Verde

Baby three toed sloth

Personal Notes on getting started with GNU/Linux & Ubuntu

I finally got around to installing a Linux distro on my machine (Ubuntu). Here are some notes that I wanted to make sure I have for future reference:

(Much of this is taken from the LearnLinux.tv YouTube channel here:)

Filesystem notes:

=
C:\Users = /home
C:\Windows = /root (This is not 100% accurate equivalency. root is actually a user that is the admin user for the machine.)
(ie USB) = /media

Terminal/BASH Cheatsheet

BASH stands for Born Again SHell

Colour codes NB: This isn't the same of every disto:
Blue = Folder
Green = Program/Binary
White = file
Teal = link/symlink(?)

BASH_CMDS

clear = clear's the terminal (eq tq cls in windows)
echo = prints what you put in quotes after the cmd (like windows does)
pwd = (print's the working directory)
~ = (shorthand/shortcut for home dir)
cat = (shows the contents of a file)
which = (show if and where a cmd/program/binary lives)
cp = (copies files)
diff = (tells you if files are different, If they're the same then there's no output)
. = refers to current dir
..  = refers to dir that's one level up from current
mv =  used for moving files but ALSO renaming files.

Nano (basic test editor (ie notepad)
^ refers to Ctrl so Ctrl+G shows the help menu.

Bash scripting:

All scripts must start with a "Hash Bang" aka "She Bang": 

#!/bin/bash

You must make the bash file you've save an executable with:
chmod +x your_filename

Setting Variables

var_name=
NB: Whitespace is not allowed
eg:
msg="Hi There"
number=10

Addressing Variables

use $ as a prefix
eg:
echo $msg
echo $number

You can pass variables to the bash script. Address them using $ where is the number of the argument.

eg:
echo $1  # prints out first arg passed 
echo $2  # prints our second arg passed

If/Else syntax

if [ $MY_VAR -eq 200 ]
then
    echo "my var is equal to 200"
else
    echo "ma var is not equal to 200"
fi