I'm taking a grid, seperating out the prims and extruding the faces. If I use a partitian sop before the extrude I can create a group for each prim by putting grid_$PR in the Rule parameter.
When I extrude the prims, the groups go away.
Is there an easy way to group objects based on volume? Each closed shape needs to be its' own seperate group.
Any ideas?
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Technical Discussion » Groups based on volume?
- the_squid
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Houdini Lounge » Houdini 8..... THANKYOU
- the_squid
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I've only had the time to look through the demo files and play around a bit with the wire solver at home, but let me just say from what I've already seen this is such an awesome addition to the toolset I am really, really excited and looking forward to learning more about it.
I've been whining and complaining and begging for some sort of clue as to when this version would be released, and I have to say it was definately worth the wait.
The fact that it was available for download July 27th made things even better, since that was my birthday!
So thanks for making this incredible software even more powerful, and for making my birthday 100x's sweeter. It really made my day!
p.s. the Maya, Max, and Lightwave guys where I work are all extremely interested in the stuff I've been showing them in v8. They all downloaded the apprentice version and I've never seen them so determined to learn the software. I think this addition will help expand the Houdini community quite a bit!
I've been whining and complaining and begging for some sort of clue as to when this version would be released, and I have to say it was definately worth the wait.
The fact that it was available for download July 27th made things even better, since that was my birthday!
So thanks for making this incredible software even more powerful, and for making my birthday 100x's sweeter. It really made my day!
p.s. the Maya, Max, and Lightwave guys where I work are all extremely interested in the stuff I've been showing them in v8. They all downloaded the apprentice version and I've never seen them so determined to learn the software. I think this addition will help expand the Houdini community quite a bit!
Houdini Lounge » Particle Collision
- the_squid
- 132 posts
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Also… if all else fails, crank up your oversampling from 1 to 2 or even 3 or 4, depending on how quickly your particles are moving. Increasing collision tolerance may resolve the issue but could cause particles to collide before they hit the surface. Oversampling forces your pops to compute in-between frames, so any particles which may be flying through your geometry between frames will be addressed.
Good luck!
Good luck!
Houdini Lounge » Remember Dial-Up?
- the_squid
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Technical Discussion » Maya Channels to Houdini
- the_squid
- 132 posts
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Thanks for the input! I've been pulled onto another task but I'll get back to this one next week. Jeffrey emailed me back with some info.
People looking through this thread may find this useful:
“First off, let me apologize for the un-user friendliness of the script It's in dire need of a rewrite.
If you have python installed on your machine, it should be as easy as typing ”python <scriptname>" into a shell (or dos prompt, if you're in windows). If you do not have python installed, you can download it from here:
http://www.python.org/2.4.1/ [python.org]
It's available for most every operating system in service, so you shouldn't have any problems getting it up and running.
Please let me know if I can do anything else to help out!
–Jeff"
People looking through this thread may find this useful:
“First off, let me apologize for the un-user friendliness of the script It's in dire need of a rewrite.
If you have python installed on your machine, it should be as easy as typing ”python <scriptname>" into a shell (or dos prompt, if you're in windows). If you do not have python installed, you can download it from here:
http://www.python.org/2.4.1/ [python.org]
It's available for most every operating system in service, so you shouldn't have any problems getting it up and running.
Please let me know if I can do anything else to help out!
–Jeff"
Technical Discussion » Maya Channels to Houdini
- the_squid
- 132 posts
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How do I run the Python script itself? What I'm missing is a way to execute the script in either Maya or Houdini.
Technical Discussion » Maya Channels to Houdini
- the_squid
- 132 posts
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I downloaded the Liaison script but I'm having some trouble getting it working.
I followed the directions:
1.) I opened a fresh Maya scene and a fresh Houdini scene. I went into Maya's script editor and typed:
commandPort -name “:2222”;
Then I opened my Houdini file (textport) and typed:
openport 500
2.) I opened up the “liaison_v1.0.030b.py” script and replaced the variables with my own camera name, file path's, etc.
3.) ……???
Here is the online documentation:
http://www.thebeeland.net/liaison/tech_desc.htm [thebeeland.net]
I'm not sure what to do now. The documentation for this script is pretty limited, as is my knowledge of working with Python scripts… any suggestions?
I followed the directions:
1.) I opened a fresh Maya scene and a fresh Houdini scene. I went into Maya's script editor and typed:
commandPort -name “:2222”;
Then I opened my Houdini file (textport) and typed:
openport 500
2.) I opened up the “liaison_v1.0.030b.py” script and replaced the variables with my own camera name, file path's, etc.
3.) ……???
Here is the online documentation:
http://www.thebeeland.net/liaison/tech_desc.htm [thebeeland.net]
I'm not sure what to do now. The documentation for this script is pretty limited, as is my knowledge of working with Python scripts… any suggestions?
Technical Discussion » baking/freezing a displacement to polys
- the_squid
- 132 posts
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One way to do this is by setting up a simple SOP network that reads an image and apply's point color information to points, and then uses that point color information to displace points in a pointSOP.
In COPs, append a fileCOP and source your displacement image there. In my case I called this node “displace_file.”
In SOPs, take the geometry you're wanting to displace and append a pointSOP (after your UV's have been projected). In the point SOP, you're going to adjust your position by overriding the default $TX,$TY,$TZ with:
$TX+(pic(“/img/img1/displace_file”,$MAPU,$MAPV,D_CLUM)*$NX)*1
$TY+(pic(“/img/img1/displace_file”,$MAPU,$MAPV,D_CLUM)*$NY)*1
$TZ+(pic(“/img/img1/displace_file”,$MAPU,$MAPV,D_CLUM)*$NZ)*1
“D_CLUM” will take the luminance value of your image and use that to apply the displacement.
If you want more help on this function, open a textport and type:
exhelp pic
Notice I multiply the pic() function by $NX,$NY,$NZ. This should point the displacement in the direction of the normals. The multiplier at the end sets the amount of displacement.
This method will not necessarely duplicate the exact kind of displacement you're getting through the shader but should help with as an aid in visualization.
In COPs, append a fileCOP and source your displacement image there. In my case I called this node “displace_file.”
In SOPs, take the geometry you're wanting to displace and append a pointSOP (after your UV's have been projected). In the point SOP, you're going to adjust your position by overriding the default $TX,$TY,$TZ with:
$TX+(pic(“/img/img1/displace_file”,$MAPU,$MAPV,D_CLUM)*$NX)*1
$TY+(pic(“/img/img1/displace_file”,$MAPU,$MAPV,D_CLUM)*$NY)*1
$TZ+(pic(“/img/img1/displace_file”,$MAPU,$MAPV,D_CLUM)*$NZ)*1
“D_CLUM” will take the luminance value of your image and use that to apply the displacement.
If you want more help on this function, open a textport and type:
exhelp pic
Notice I multiply the pic() function by $NX,$NY,$NZ. This should point the displacement in the direction of the normals. The multiplier at the end sets the amount of displacement.
This method will not necessarely duplicate the exact kind of displacement you're getting through the shader but should help with as an aid in visualization.
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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I downloaded the wisp VOP. The readme says:
this contains vex code for a POP and a sample .hip utilizing this POP.
the POP rotates the motion of the particles around the transverse
to the gradient of a noise function. This gives you cool vortexes
and wispy swirling motion.
-Ivan
==========
I've never loaded in VEX code. How do I do it? The compressed folder I downloaded contains these files:
wisp.vfl
README
wisp.hip
VEXpop
Some hand holding will be required here…
this contains vex code for a POP and a sample .hip utilizing this POP.
the POP rotates the motion of the particles around the transverse
to the gradient of a noise function. This gives you cool vortexes
and wispy swirling motion.
-Ivan
==========
I've never loaded in VEX code. How do I do it? The compressed folder I downloaded contains these files:
wisp.vfl
README
wisp.hip
VEXpop
Some hand holding will be required here…
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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// Code produced by: print1
text = sprintf(“v: %f\tfval1: %f\tfval2: %f\tfval3: %f”, v, fval1, fval2, fval3);
printf(“v: %f\tfval1: %f\tfval2: %f\tfval3: %f\n”, v, fval1, fval2, fval3);
================
I was able to view the correct values finally after setting all of my new pop parameters to 0.
I have two pops. One is a source and one is the new pop I'm making in VOPS. I have my pops in view, my new VOP pop is displayed and I'm able to see the changes I make at the VOP level affect my pops. Life is good.
I have my print hooked up to my original velocity (first value) and hooked into my vector to float conversion (second value). If I set all of my noise values to 0 the values I get back in the “print” are correct. However, the second I introduce noise this all changes and I see different results. I'm wondering now if the noise VOP I'm creating is actually reading from the noise VOP I'm using in pops…
Sound familiar? Anybody else ever have this issue? Again, I'm new to VOPs and it's very possible I'm doing something I shouldn't be. See anything wrong with my setup from what I've written?
text = sprintf(“v: %f\tfval1: %f\tfval2: %f\tfval3: %f”, v, fval1, fval2, fval3);
printf(“v: %f\tfval1: %f\tfval2: %f\tfval3: %f\n”, v, fval1, fval2, fval3);
================
I was able to view the correct values finally after setting all of my new pop parameters to 0.
I have two pops. One is a source and one is the new pop I'm making in VOPS. I have my pops in view, my new VOP pop is displayed and I'm able to see the changes I make at the VOP level affect my pops. Life is good.
I have my print hooked up to my original velocity (first value) and hooked into my vector to float conversion (second value). If I set all of my noise values to 0 the values I get back in the “print” are correct. However, the second I introduce noise this all changes and I see different results. I'm wondering now if the noise VOP I'm creating is actually reading from the noise VOP I'm using in pops…
Sound familiar? Anybody else ever have this issue? Again, I'm new to VOPs and it's very possible I'm doing something I shouldn't be. See anything wrong with my setup from what I've written?
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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When I do my conversions from vector to float value's I'm getting strange results.
I'm using a “vector to float” VOP and piping the “v” from “Global Variables” into it. The vector values I get before the conversion are:
v: {0.404275,1.624916,0.659920}
Converted through a vector to float VOP they become:
fval1: 0.008625 fval2: 1.215465 fval3: 0.444304
I assume this may be normal but it's not what I want. I thought by using “vector to float” I'd be able to easily seperate out my X, Y and Z values. There are other ways to seperate these values, but now I'm wondering what the vector to float is usually used for.
I'm using a “vector to float” VOP and piping the “v” from “Global Variables” into it. The vector values I get before the conversion are:
v: {0.404275,1.624916,0.659920}
Converted through a vector to float VOP they become:
fval1: 0.008625 fval2: 1.215465 fval3: 0.444304
I assume this may be normal but it's not what I want. I thought by using “vector to float” I'd be able to easily seperate out my X, Y and Z values. There are other ways to seperate these values, but now I'm wondering what the vector to float is usually used for.
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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The “print VOP”…. OF COURSE!!!
Well that certainly helps. By the way, in Windows if you dont start from a console but toggle on “Output Text to Console” it creates a new window and prints your values there. Very cool! Thanks for the responses. I now have some better noise but it's still clearly biased in one direction. I hooked color into the noise as well so I can see what it's doing a bit better.
Using the print VOP will help me get to the bottom of this a lot faster
Well that certainly helps. By the way, in Windows if you dont start from a console but toggle on “Output Text to Console” it creates a new window and prints your values there. Very cool! Thanks for the responses. I now have some better noise but it's still clearly biased in one direction. I hooked color into the noise as well so I can see what it's doing a bit better.
Using the print VOP will help me get to the bottom of this a lot faster
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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“(by the way, is there a way to visualize numeric outputs from VOPs?)”
This is kind of a stupid question since everything done in Houdini can be seen…. I could look at my velocity values from my source pops, then look at the new values from my noise VOP, and get the difference from there. However it may be cool to have a spreadsheet type view available within the VOP editor. I'm curious how other artists are looking at the math behind the curtains…
This is kind of a stupid question since everything done in Houdini can be seen…. I could look at my velocity values from my source pops, then look at the new values from my noise VOP, and get the difference from there. However it may be cool to have a spreadsheet type view available within the VOP editor. I'm curious how other artists are looking at the math behind the curtains…
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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Update:
Okay, it is becoming clear to me that in order to do this correctly I have to familiarize myself more with the way a VOP_particle network should work.
I've decided to ditch my “boids” idea for a much more simple excersize to get me on the right path. My goal now is to create a nice 3D noise field (which will act somewhat like turbulence) for my particles to fly through.
Simple enough, right?
So far I have my VOP network setup like this:
I bring in my pop info from a “global variable” pop. I pipe EVERYTHING out through the output variables pop and make sure the newly created pop is working correctly (i.e. not doing anything.) After I do this I lay down 3 turbulence VOPs so I can add noise in X, Y, and Z seperately. I attach parameters to the frequency, offset, and amplitude inputs on my noise so I have control over them in pops (I control amplitude for X, Y, and Z seperately but my offsets and frequency work on all turbulence VOPs at once.)
After I do this I take my particle velocity information and strip it out into x,y,z values using a vector_to_float VOP.
Here's where I go wrong…. (unless I've already gone wrong which is highly likely). In order to add the noise to my particles I'm using an “add” VOP and adding the turbulence values to my stripped out X, Y, and Z values. So I have three turbulences, one for each axis, being added to my velocity in x, y, and z seperately.
This may work if the only value returned from my noise was -1 to 1 but I assume it's not (by the way, is there a way to visualize numeric outputs from VOPs?) The result I get is interesting but not what I want. My particles are clearly biased in one direction from my having added the turbulence to each axis instead of introducing it in some other way.
I'm certain there's a better way for doing something like this properly. I know the way I'm approaching this isn't very elegant so any input to steer me in the right direction woud be appreciated.
Okay, it is becoming clear to me that in order to do this correctly I have to familiarize myself more with the way a VOP_particle network should work.
I've decided to ditch my “boids” idea for a much more simple excersize to get me on the right path. My goal now is to create a nice 3D noise field (which will act somewhat like turbulence) for my particles to fly through.
Simple enough, right?
So far I have my VOP network setup like this:
I bring in my pop info from a “global variable” pop. I pipe EVERYTHING out through the output variables pop and make sure the newly created pop is working correctly (i.e. not doing anything.) After I do this I lay down 3 turbulence VOPs so I can add noise in X, Y, and Z seperately. I attach parameters to the frequency, offset, and amplitude inputs on my noise so I have control over them in pops (I control amplitude for X, Y, and Z seperately but my offsets and frequency work on all turbulence VOPs at once.)
After I do this I take my particle velocity information and strip it out into x,y,z values using a vector_to_float VOP.
Here's where I go wrong…. (unless I've already gone wrong which is highly likely). In order to add the noise to my particles I'm using an “add” VOP and adding the turbulence values to my stripped out X, Y, and Z values. So I have three turbulences, one for each axis, being added to my velocity in x, y, and z seperately.
This may work if the only value returned from my noise was -1 to 1 but I assume it's not (by the way, is there a way to visualize numeric outputs from VOPs?) The result I get is interesting but not what I want. My particles are clearly biased in one direction from my having added the turbulence to each axis instead of introducing it in some other way.
I'm certain there's a better way for doing something like this properly. I know the way I'm approaching this isn't very elegant so any input to steer me in the right direction woud be appreciated.
Houdini Lounge » Question for the developers: FBX Support?
- the_squid
- 132 posts
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Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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Thanks guys these responses have been really helpful. The bugbrainz plugin by Carsten Kolve is pretty slick! Now I just have to replicate the same kind of thing in Houdini… thanks again for the input so far!
Technical Discussion » VOPs Flocking
- the_squid
- 132 posts
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I haven't really gotten into the thick of this experiment but I'd like to describe a theoretical solution to flocking which I plan on setting up in VOPs. This is my second particle operator I've built through VOPs so I'm really new to the pipeline.
I would like to replicate the “boids” model seen here:
http://www.red3d.com/cwr/boids/ [red3d.com]
By casting a cone of rays out in the direction of my particles velocity and letting those rays bounce off other particles I'd like to determine the location of other particles and adjust my velocity based on what my particle “see's.”
Any help or links you could offer would help. I'll be working on this today as an excersize and will update when I make some progress or run into any walls…
I could use any VOPs/VEX tips out there and have been finding a lot online already, any more links you could offer will probably help.
I would like to replicate the “boids” model seen here:
http://www.red3d.com/cwr/boids/ [red3d.com]
By casting a cone of rays out in the direction of my particles velocity and letting those rays bounce off other particles I'd like to determine the location of other particles and adjust my velocity based on what my particle “see's.”
Any help or links you could offer would help. I'll be working on this today as an excersize and will update when I make some progress or run into any walls…
I could use any VOPs/VEX tips out there and have been finding a lot online already, any more links you could offer will probably help.
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