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Technical Discussion » Replace all local paths by relative ($JOB / $HIP) in a scene?
- Andi Farhall
- 115 posts
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I think opchange in an hscript window might do it. I've bulk changed file paths before with it.
Houdini Lounge » Dopnets inside geo nodes - viewport oddness
- Andi Farhall
- 115 posts
- Offline
Houdini Lounge » Dopnets inside geo nodes - viewport oddness
- Andi Farhall
- 115 posts
- Offline
Hi all,
when I dive into a dopnet that's inside a geo node everything in the viewport disappears, (yes, show all objects is set) but a dopnet at the object level behaves as expected. I'm confused to say the least. Tried a new vieport, no dice, tried v18 instead 17.5, no dice. Can't find any preferences for it…. stumped.
cheers,
A>
when I dive into a dopnet that's inside a geo node everything in the viewport disappears, (yes, show all objects is set) but a dopnet at the object level behaves as expected. I'm confused to say the least. Tried a new vieport, no dice, tried v18 instead 17.5, no dice. Can't find any preferences for it…. stumped.
cheers,
A>
Technical Discussion » World space hack, what am I missing.
- Andi Farhall
- 115 posts
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“where things are” in houdini isn't a simple question… One habit I've got into is driving a transform node srt with a null at object level using relative referencing, which won't work if there's any hierarchy involved, so evolving from that i managed to get world position and rotation for an object, (hierachy or not) by using the Reference>scene data where you can access the world position and rotation of an obj level object. That has to happen inside and obj level “control object” (at 0,0,0)and then the values can be referenced outside by anything in the usual way.
It certainly works for me in this specific instance, but - given every time i have an aha moment it's followed 3 weeks later by an actually i've no idea what's going moment, I wondering what could be wrong with my setup. I know information about world space is something people request regularly so i'm dubious it was that simple for me to stumble across.
I've referenced the values back on to the node i'm interested in for handiness.
Hip attached
cheers,
A>
It certainly works for me in this specific instance, but - given every time i have an aha moment it's followed 3 weeks later by an actually i've no idea what's going moment, I wondering what could be wrong with my setup. I know information about world space is something people request regularly so i'm dubious it was that simple for me to stumble across.
I've referenced the values back on to the node i'm interested in for handiness.
Hip attached
cheers,
A>
Houdini Lounge » Anything in the pipeline for liquids?
- Andi Farhall
- 115 posts
- Offline
Scale is an interesting point as I've always tried to work to real world units so my particle separation is heading towards 0.005 or lower. Never tried working at a hacked scale as I've no idea which parameters need tweaking to accommodate it apart from gravity obviously. Is it a smarter move to simulate at an optimum size and scale down the end surface?
I seem to have problems when simulating anything with that has a finer thinner quality to it ending up with volume loss, or clinging to surfaces. I've uploaded a simple test to illustrate what i'm currently trying to create. A garden feature where the water bubbles out the top of a pole and flows down the outside. Simple but the water needs to be the star of the idea.
I've a very rudimentary grasp of what flip is doing… gleaned from Steve Knippings cg circuit flip series, but I've no idea how to debug flips behaviour, or go beyond the basic setups. I know for sure you don't master flips in H with the occasional sim over 12 months, but I've come from bashing stuff out quickly in Softimage and Realflow to taking a fair bit longer in H and the boss is tapping his foot!
cheers,
Andi
I seem to have problems when simulating anything with that has a finer thinner quality to it ending up with volume loss, or clinging to surfaces. I've uploaded a simple test to illustrate what i'm currently trying to create. A garden feature where the water bubbles out the top of a pole and flows down the outside. Simple but the water needs to be the star of the idea.
I've a very rudimentary grasp of what flip is doing… gleaned from Steve Knippings cg circuit flip series, but I've no idea how to debug flips behaviour, or go beyond the basic setups. I know for sure you don't master flips in H with the occasional sim over 12 months, but I've come from bashing stuff out quickly in Softimage and Realflow to taking a fair bit longer in H and the boss is tapping his foot!
cheers,
Andi
Houdini Lounge » Anything in the pipeline for liquids?
- Andi Farhall
- 115 posts
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Looking for thoughts and opinions on this.. From the horses mouth would be amazing too.
I'm wondering if there are plans to do anything on a grander scale for liquid simulations (not really biblical floods or oceans but smaller scale stuff)? Does anyone think it needs work? I'm looking for solutions to my issue(s) with it not looking to grumble about it not working.
I have to say first up I've only been using H for 12 months so I'm a total beginner with all the problems that brings so the question comes from that perspective. Liquids or rather flip seems to be the only part of H I've not been able to get in any way comfortable with. My experience of liquids pre H is small scale uncomplicated stuff done in realflow, laterly using dyverso. I never used hybrido as the sph solver was fast enough for my needs and I could turn simple stuff out without issue. Flip in H seems like a different beast and I've really got nowhere with it. A fair few voices suggest that flip has things it's good for and things it's not and that seems to be backed up up by the kind of tutorials and masterclasses that are available.
Looking at doing some small garden water feature designs recently and after a few weeks if fidling around with flip I've felt like I should just do it in Realflow to get it done but that seems like a massive cop out and I don't have time or money to use multiple bits of software. Using the result of following a tutorial is a good start but after that I've only to breathe on a setup/parameter and it instantly turns to garbage and advice from forums seems to be unwieldingly varied.
So, more questions than my inital one… Do people who really know about it think liquids need looking at? Is a third party solution a necessary evil at this time? or Is it really just time and experience that one needs to be able to achieve quick, simple small scale liquids.
cheers,
Andi
I'm wondering if there are plans to do anything on a grander scale for liquid simulations (not really biblical floods or oceans but smaller scale stuff)? Does anyone think it needs work? I'm looking for solutions to my issue(s) with it not looking to grumble about it not working.
I have to say first up I've only been using H for 12 months so I'm a total beginner with all the problems that brings so the question comes from that perspective. Liquids or rather flip seems to be the only part of H I've not been able to get in any way comfortable with. My experience of liquids pre H is small scale uncomplicated stuff done in realflow, laterly using dyverso. I never used hybrido as the sph solver was fast enough for my needs and I could turn simple stuff out without issue. Flip in H seems like a different beast and I've really got nowhere with it. A fair few voices suggest that flip has things it's good for and things it's not and that seems to be backed up up by the kind of tutorials and masterclasses that are available.
Looking at doing some small garden water feature designs recently and after a few weeks if fidling around with flip I've felt like I should just do it in Realflow to get it done but that seems like a massive cop out and I don't have time or money to use multiple bits of software. Using the result of following a tutorial is a good start but after that I've only to breathe on a setup/parameter and it instantly turns to garbage and advice from forums seems to be unwieldingly varied.
So, more questions than my inital one… Do people who really know about it think liquids need looking at? Is a third party solution a necessary evil at this time? or Is it really just time and experience that one needs to be able to achieve quick, simple small scale liquids.
cheers,
Andi
Technical Discussion » Getting my head round the solver sop.
- Andi Farhall
- 115 posts
- Offline
Thanks mrCatfish,
that works perfectly, vops rather than vex and wrangles is much more familiar given my softimage history but somethings tells me i'll need to grasp vex properly at some point as i've zero coding experience whatsoever. Am I right in thinking that groups are actually just attributes under the hood?
that works perfectly, vops rather than vex and wrangles is much more familiar given my softimage history but somethings tells me i'll need to grasp vex properly at some point as i've zero coding experience whatsoever. Am I right in thinking that groups are actually just attributes under the hood?
Technical Discussion » Getting my head round the solver sop.
- Andi Farhall
- 115 posts
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Solver sop seems like a handy node if I just just figure out how to incorporate it properly. Here's my scenario:
I've a a long strip of points travelling along in X (like rocks on a conveyor) and each rock has a float attribute that's a random value between 0 and 1. When each point hits a certain position in X the random value gets added to every frame which is where I though the solver sop would come in. Then at a further position in X the counting stops, and a delete node gets rid of all the points who's random value is above a threshold.
I was using a group by bounding volume to determine where the counting should occur but I can't combine the counting bit inside the solver sop with the grouping bit that comes before.
How do I get the adding wrangle in the solver sop to use the group that's changing frame to frame.
Alternatively what other techniques would people use to achieve the same result?
cheers,
A>
I've a a long strip of points travelling along in X (like rocks on a conveyor) and each rock has a float attribute that's a random value between 0 and 1. When each point hits a certain position in X the random value gets added to every frame which is where I though the solver sop would come in. Then at a further position in X the counting stops, and a delete node gets rid of all the points who's random value is above a threshold.
I was using a group by bounding volume to determine where the counting should occur but I can't combine the counting bit inside the solver sop with the grouping bit that comes before.
How do I get the adding wrangle in the solver sop to use the group that's changing frame to frame.
Alternatively what other techniques would people use to achieve the same result?
cheers,
A>
Edited by Andi Farhall - June 5, 2020 06:08:18
Technical Discussion » Wild values in Pyro Voxels
- Andi Farhall
- 115 posts
- Offline
I though it was me and I was just breaking something but I get the same behaviour with a simple test scene. I'm viewing the values in my pyro voxels using a volume slice on the import_pyrofileds node and getting some wild density or heat values. There's the normal range I would expect 0 to 1 or suchlike, and then I'm getting values like 4.10663e-26 or -3.07336e-0 which is confusing.
Are these numbers anything to worry about? Is Houdini, and for that matter redshift ignoring them?
cheers,
Andi.
Are these numbers anything to worry about? Is Houdini, and for that matter redshift ignoring them?
cheers,
Andi.
Technical Discussion » Slip on collision causing flip to explode.
- Andi Farhall
- 115 posts
- Offline
Hi,
I'm using flip to show some water feature ideas, so it a couple of metres in scale. I've turned on viscosity just to stop the water moving so quickly but kept the value very low - 0.001, and turned on slip on surface and set the slip scale at .95. Once slip scale goes above about .8 i start getting little pops in the sim. I've checked for interpenetration between the emitter and the obstacle and it seems like there is plenty of space but my flip debugging skills end there sadly…
I assumed that turning viscosity on and keeping it low was appropriate as all liquids must have a viscosity value and I wanted the water to interact more with the surface rather than glide so effortlessly over it.
I've included the hiplc file in case anyone is bored and wants to take a look.
cheers,
Andi.
I'm using flip to show some water feature ideas, so it a couple of metres in scale. I've turned on viscosity just to stop the water moving so quickly but kept the value very low - 0.001, and turned on slip on surface and set the slip scale at .95. Once slip scale goes above about .8 i start getting little pops in the sim. I've checked for interpenetration between the emitter and the obstacle and it seems like there is plenty of space but my flip debugging skills end there sadly…
I assumed that turning viscosity on and keeping it low was appropriate as all liquids must have a viscosity value and I wanted the water to interact more with the surface rather than glide so effortlessly over it.
I've included the hiplc file in case anyone is bored and wants to take a look.
cheers,
Andi.
Edited by Andi Farhall - April 20, 2020 11:43:02
Technical Discussion » Making more complex curves
- Andi Farhall
- 115 posts
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Thanks Michael…. Infinite ways to skin a Houdini cat, and every day learn something new.
cheers,
A.
cheers,
A.
Technical Discussion » Making more complex curves
- Andi Farhall
- 115 posts
- Offline
Thanks Benny, that certainly works. To me it appears to need some convoluted thinking to have reached that solution myself but then I've only had 12 months experience at the simplest end of Houdini so my brain is still working in oldschool soft mode. Now I'm out of that hole I can crack on.
cheers,
A>
cheers,
A>
Technical Discussion » Making more complex curves
- Andi Farhall
- 115 posts
- Offline
I seem to have stumbled onto what I can only assume is a Houdini weak spot. Curves. I have to draw a path for an object which starts and ends with some straight bits and has 2 spirals in the middle, so i made the two spiral parts using the curve tool and a twist sop, and made the straight bits using the curve tool and the odd transform. Now I need them to be one curve so i plug them all into a merge sop and then a fuse. The point order is screwed and the sort sop is of no use so I'm wondering if i really need to go back to softimage just to generate this curve, or am i missing something fundamental? Attached is the simple i've been using so you can see what I've been up to.
cheers,
A.
cheers,
A.
Edited by Andi Farhall - Feb. 26, 2020 11:00:18
Technical Discussion » VIEWPORT DISPLAY BEHAVIOUR
- Andi Farhall
- 115 posts
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Technical Discussion » VIEWPORT DISPLAY BEHAVIOUR
- Andi Farhall
- 115 posts
- Offline
The only display>guides that made a difference was the Node guides which just hides the terrain object itself.
Technical Discussion » VIEWPORT DISPLAY BEHAVIOUR
- Andi Farhall
- 115 posts
- Offline
One on the left is the geo where i can see where i want the curve, the right is with the drawcurve tool selected.
cheers,
A>
cheers,
A>
Technical Discussion » VIEWPORT DISPLAY BEHAVIOUR
- Andi Farhall
- 115 posts
- Offline
Is driving me nuts….. I want to DrawCurve on to a piece of geometry terrain converted from a heightfield and I need to see the geometry properly to do so. When i select the drawcurve node the terrain basically turns almost completely blue obscuring things. How do I stop it doing that? (yes I have the display node selected on the node above the drawcurve).
The other one is the edit node, It does a similar sort of thing. I'm trying to edit the curve I've drawn, and the terrain displays all the points when i select the edit node in point select mode.
Have I missed a whole section in the manual about vieport behaviour or is this really how people work?
cheers,
Andi.
The other one is the edit node, It does a similar sort of thing. I'm trying to edit the curve I've drawn, and the terrain displays all the points when i select the edit node in point select mode.
Have I missed a whole section in the manual about vieport behaviour or is this really how people work?
cheers,
Andi.
Technical Discussion » Path constraint and sop level raycast
- Andi Farhall
- 115 posts
- Offline
Hola, newbie question…..
Simple task, drive a vehicle over a piece of terrain.
For ease of use the vehicle needs to follow a curve then stick itself to the terrain surface. Either of these things appear simple but together appears (to my beginner eyes) impossible.
My rig to stick something to a simple piece of terrain was a simple grid with 4 points, into a transform node then raycast down onto the terrain…. Use the transform node to drive around. Simple…. Now I want to use a curve to drive the position of the 4 point grid… but unsurprising to you all it's not working because of the old object level / sop level thing.
So how would you go about it?
Somehow extract the position and rotation of something constrained to the path and feed that in to grids position?
Any ideas or suggestions?
Cheers,
Andi.
Simple task, drive a vehicle over a piece of terrain.
For ease of use the vehicle needs to follow a curve then stick itself to the terrain surface. Either of these things appear simple but together appears (to my beginner eyes) impossible.
My rig to stick something to a simple piece of terrain was a simple grid with 4 points, into a transform node then raycast down onto the terrain…. Use the transform node to drive around. Simple…. Now I want to use a curve to drive the position of the 4 point grid… but unsurprising to you all it's not working because of the old object level / sop level thing.
So how would you go about it?
Somehow extract the position and rotation of something constrained to the path and feed that in to grids position?
Any ideas or suggestions?
Cheers,
Andi.
Edited by Andi Farhall - Sept. 26, 2019 13:51:07
Technical Discussion » creep sop and polysplit in the same network
- Andi Farhall
- 115 posts
- Offline
cheers for that, might take a while to work my way through a massive piece of geo but at least there's a fix. Could this behavior be considered a bug do you think? It's certainly not first choice behavior so I might put a feature request or bug report in.
Technical Discussion » creep sop and polysplit in the same network
- Andi Farhall
- 115 posts
- Offline
Hi all,
i know my noob brain is to blame here…. I'm using the creep sop to flow some points over a surface which works well, until i want to edit the base mesh with polysplit. Without polysplit the convert node to turn polymesh into nurbs surface says I have 1 nurbs surface as I would expect, but adding an edgeloop i now get 90 individual nurbs surfaces and my flowing points are understandably only flowing in the first one. I don't fully understand geometry in houdini as it's so different to other software and I imagine this is part of the problem. I've tried a shed load of convert options, nurbs nodes, remesh, sort… the list goes on but no dice.
Any clues?
Using 17.0.059 Win7
cheers,
Andi.
Uploaded a simple hip just in case…
i know my noob brain is to blame here…. I'm using the creep sop to flow some points over a surface which works well, until i want to edit the base mesh with polysplit. Without polysplit the convert node to turn polymesh into nurbs surface says I have 1 nurbs surface as I would expect, but adding an edgeloop i now get 90 individual nurbs surfaces and my flowing points are understandably only flowing in the first one. I don't fully understand geometry in houdini as it's so different to other software and I imagine this is part of the problem. I've tried a shed load of convert options, nurbs nodes, remesh, sort… the list goes on but no dice.
Any clues?
Using 17.0.059 Win7
cheers,
Andi.
Uploaded a simple hip just in case…
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