Houville :: customising node attributes

Create a text file called "OPcustomize" in your houdini16.0 (or corresponding) folder. Here you can describe the new defaults you want to use with your nodes. For colours

opdefaultcolor Sop null 'RGB 0.0 0.0 0.0';
opdefaultcolor Sop dopnet 'RGB 0.5 0.0 0.0';
opdefaultcolor Sop dopimport 'RGB 0.5 0.0 0.0';
opdefaultcolor Sop object_merge 'RGB 0.475 0.812 0.204';

Thanks to Amber for this one.

Going beyond this:

We can grab the type from a python shell with drag-drop then append ".type()". And we can also work with default and user-defined shapes, and grab the colour info.

# good if you manually selected a new shape.
n.userData("nodeshape");

# good for finding the session default shape for the node
n.type().defaultShape();

# for getting the colour that has been user assigned
n.color()

Example:

opdefaultcolor Driver null 'RGB 0.478 0.478 0.478';
opdefaultshape Driver null 'circle';
opdefaultcolor Driver merge 'RGB 0.65 0.65 0.65';
opdefaultshape Driver merge 'circle';
opdefaultcolor Driver geometry 'RGB 0.145 0.667 0.557';
opdefaultshape Driver geometry 'tabbed_left';

opdefaultcolor Driver gridmarkets::render_submit::1.5.2 'RGB 0.45 0.12 0.6';
opdefaultcolor Driver gridmarkets::nuke::1.19 'RGB 0.976 0.78 0.263';

opdefaultcolor Driver gridmarkets::transcode::1.8 'RGB 0.25 0.5 1';
opdefaultshape Driver gridmarkets::transcode::1.8 'wave';
opdefaultcolor Driver ifd 'RGB 1 .976 0.666';

opdefaultcolor Sop null 'RGB 0.0 0.0 0.0';
opdefaultcolor Sop dopnet 'RGB 1 0 0';
opdefaultcolor Sop gridmarkets::cloud_cache::1 'RGB 0.145 0.667 0.557';
opdefaultshape Sop gridmarkets::cloud_cache::1 'tabbed_left';
opdefaultcolor Sop file 'RGB 0.616 0.871 0.769';

Inspiration :: "No Face"

NO FACE – 千と千尋の神隠し from Raoul Marks – MARXº on Vimeo.

Inspiration :: "Slow Wave"

Slow Wave from andy kennedy on Vimeo.

Houville :: how to not go insane with Nuke vs Houdini hotkeys

Display shortcuts: I have these set as F9-F12

import os,glob
def visualise(flag):
    if flag ==1: hou.selectedNodes()[0].setDisplayFlag(1)
    if flag ==2: hou.selectedNodes()[0].setRenderFlag(1)
    if flag ==3:
        if len(hou.selectedNodes())>0:
            state = 1-hou.selectedNodes()[0].isTemplateFlagSet()
            for i in hou.node(os.path.dirname(hou.selectedNodes()[0].path())).glob('*'): i.setTemplateFlag(0)
            for i in hou.selectedNodes():
                i.setTemplateFlag(state)
    if flag ==4:
        state = 1-hou.selectedNodes()[0].isBypassed()
        for i in hou.selectedNodes():
            i.bypass(state)

visualise(4)

This is straight out of Nukeland for snapping your nodes to the grid intersections. I have it set as Shift+\

And finally the most common one I need to not yell at the everlasting cookfests. I have it set to Alt+Shift+U, which is a bit Vulcan MindMeldy but it works. I also set Alt+U to "/Houdini/Force Update"

import hou
mode = hou.updateModeSetting().name()
if mode == 'AutoUpdate':
    hou.setUpdateMode(hou.updateMode.Manual)
if mode == 'Manual':
    hou.setUpdateMode(hou.updateMode.OnMouseUp)
if mode == 'OnMouseUp':
    hou.setUpdateMode(hou.updateMode.AutoUpdate)

NukeStudio :: Return the source path for a selected clip

from hiero.core import TrackItem
seq = hiero.ui.activeSequence()
te = hiero.ui.getTimelineEditor(seq)
t =te.selection()[-1]
print t.source().mediaSource().fileinfos()[0].filename()

NukeStudio :: Text expression to display media info

Use this to get file name of the displayed media in NukeStudio:

[lindex [split [metadata input/filename] "/"] end]

Alternatively...

if you have a comp clip on the time line, this will help you get the internal frame number:
[metadata input/frame]

For Shot name:
[metadata hiero/shot]


For Clip name:
[metadata hiero/clip]


For the file path of the Clip:
[metadata input/filename]


For the Sequence time frame no.
[frame]

For the source clip frame number:
[metadata input/frame]

Houville :: nice up vectors

This is for arranging your geo for nice behaviour with the copy sop. If you want to distibute geo, like trees or whatever, and control orientation but still respect the angle to the surface this is for you.


You'll need some way to connect the target points with the surface prim they relate to. Scatter has the sourceprim option which is cool, but if you want to manually do it you'll need a pre-pass. Here's an example using the 'stick a point in the middle of the face' technique. This should run over prims.

int newPtNum = addpoint(0,@P);
addpointattrib(0,"sourceprim", 0);
setpointattrib(0,"sourceprim", newPtNum, @primnum, 'set');
removeprim(0,@primnum,1);

Now lets get the surface geo ready. Here we will sneakily say normals run along the U direction and Up is what would typically be considered a normal. This makes sure our orientation makes sense.

Run this over points, assuming point source is in OpInput1, and reference geo for orientation is OpInput2.

vector center = primuv(s@OpInput2, 'P', i@sourceprim, {0.5,0.5,0.0});
vector dPdu = primuv(s@OpInput2, 'P', i@sourceprim, {0.51,0.5,0.0});
vector dPdv = primuv(s@OpInput2, 'P', i@sourceprim, {0.5,0.51,0.0});

vector u = normalize(dPdu - center);
vector v = normalize(dPdv - center);

v@up = normalize(cross(u,v));
v@N = u;

//matrix rotation shiz!
vector rot[];
rot[0] = u;
rot[1] = v@up;
rot[2] = v;
matrix3 mtx[] = unserialize(serialize(rot));
rotate(mtx[0], radians(chf('heading')), v@up);
rot = unserialize(serialize(mtx));
v@N = rot[0];
v@up = rot[1];

** for another post - passing colour information through points to be picked up by "Point Instance Procedural" as material overrides:

string r = sprintf("%d", @Cd.x);
string g = sprintf("%d", @Cd.y);
string b = sprintf("%d", @Cd.z);


s@shop_materialpath = chs('../theInstancesShaderPath');
s@material_override = "{'basecolorr':" + r + ",'basecolorg':" + g + ",'basecolorb':" + b + ",}";

Soooooo.. some of that was overkill. Here are a few ways to optimise that.

You can for example dispense with the serialise/unserialise phase by seting to the matrix directly. Also you can use quarternion to directly pull rotation information out of the matrix. Bear in mind Houdini understands '@orient' as a vector4 aka p@orient.

## direct casting and assignment of a matrix, rotation, extraction as a quaternion.
matrix3 rot = set(u,v@up,v)
rotate(rot, radians(chf('heading')), v@up);
p@orient = quaternion(rot)

And finally, you don't have to derive a @up if you have a normal. Have the points (scattered or otherwise) pick up their normals from the source they are based on. addpointattrib(0,"N",{0,0,0}); setpointattrib(0,"N",newPtNum,@N,"set");