Houdini-and-Chill

Useful trick for filtering 3D tracked cameras:
“`
/* SMOOTHCAM
turn on constraints on your camera. add a constraint network (green squiggle button)
jump into the constraintnetwork. drop a “TransformWrangle and paste this code. press the create spare parameters button.
set the targetdistance to somwhere a ways away from the camera usually somwhere in the middle of your 3d tracked pointcloud enable the orange outputflag on the tranwsformwrangle
connect the getworldspace to input 0 of the wrangle.
drop a Filter set common/units to frames and perhaps something like 15 frames filterwidth and a couple of passes.
connect the filtered version of getworldspace to input1 on the wrangle
on the getworldspace set to ../.. and make sure its channel range is set to “use full animation range” or even longer to get good “ends” on your filter
remember to extend your cam animation with plausible slopes to get good filtering */
chopTRS c0 = c->fetchInput(0); chopTRS c1 = c->fetchInput(1);
matrix m0 = c->fetchInputMatrix(0); matrix m1 = c->fetchInputMatrix(1);
float dist=chf(“targetdistance”);
vector source=set(0,0,0)*m1; vector target=set(0,0,-dist)*m0; vector up=set(0,10,-dist)*m0;
up=normalize(up-target);
matrix3 orient=lookat(source,target,up); matrix TM=matrix(orient); vector rot=cracktransform(0,0,1,0,TM);
// Set transform @t = source; @r = rot;
“`

this helps by filtering the position of the camera but making sure that the pointing of the camera is unaffected at the target point distance so none of your position jitter ends up shaking your 3d track.

a classic use case is if an object is supposed to be really close to the camera but most of your tracking dots are some ways away.

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for `mat3`, & isn’t required because `mat3` is an array of vectors (`fpreal3[3]`) arrays are passed as pointers to the first element, so `mat3` is already a pointer type
this isn’t true for `mat2` and `mat4` though, since they are vector types

i started working on an opencl page today, will add more examples/sections later. it’s missing a lot of basic info at the moment github.com/MysteryPancake/Houdini-OpenCL pls abuse me if i made any horrible mistakes

like so:

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thanks man these are nice. he is using polycut, nice use case for this node

Anyone know the nodegraphtitle.py trick? I searched here but there is no mention of it. If you override this file in your user directory, you can have custom stats on the network editor like this (top left).

I use this code:
“`python from __future__ import print_function import hou import nodegraphprefs as prefs
def networkEditorTitleLeft(editor): try: title = ‘\n’
#title += “Viewport\n\n”
selectedNodes = hou.selectedNodes() if len(selectedNodes) == 1 and hou.ui.updateMode() == hou.updateMode.AutoUpdate: currentNode = selectedNodes[0] nodePath = currentNode.path()
#title += str(len(currentNode.geometry().points())) ptcount = int(hou.hscriptExpression(“npoints(\”” + nodePath + “\”)”)) primcount = int(hou.hscriptExpression(“nprims(\”” + nodePath + “\”)”))
title += str(f'{ptcount:,}’) + ” points\n” title += str(f'{primcount:,}’) + ” prims\n\n”
opinfo = hou.hscript(“opinfo -n ” + nodePath)[0]
if “Memory: ” in opinfo: memory = opinfo.split(“Memory: “)[1].split(“\n”)[0] if ‘;’ in memory: # Split the text at the first ‘;’ occurrence parts = memory.split(‘;’, 1) # Rejoin with the second part encapsulated in parentheses memory = f”{parts[0]} ({parts[1].strip()})” title += memory + “\n”
cooktime = opinfo.split(“Last Cook Time: “)[1].split(“\n”)[0] title += cooktime + “\n\n”
screenbounds = editor.screenBounds() # Figure out how much we need to scale the current bounds to get to # a zoom level of 100 pixels per network editor unit. bounds = editor.visibleBounds() currentzoom = editor.screenBounds().size().x() / bounds.size().x() title += “{:0.2f}%\n”.format(currentzoom)
“`

“`python pwd = editor.pwd() playerparm = pwd.parm(‘isplayer’) if playerparm is not None and playerparm.evalAsInt() != 0: title += ‘Network in Playback Mode\n’ if prefs.showPerfStats(editor): profile = hou.perfMon.activeProfile() if profile is not None: profiletitle = profile.title() if not profiletitle: profiletitle = ‘Profile ‘ + str(profile.id()) title += profiletitle + ‘: ‘ + prefs.perfStatName(editor)
except: title = ”
return title
def networkEditorTitleRight(editor): try: title = ” pwd = editor.pwd() title += pwd.childTypeCategory().label()
except: title = ”
return title “`

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