Found 24 posts.
Search results Show results as topic list.
Houdini Lounge » Nvidia rtx 4090 driver issues?
-
- wes_sin
- 27 posts
- Offline
This is still an issue with vellum grain in my case, I am using H19.5.458, rtx4090 driver version 527.26. Inside vellum solver, the ocl_neighboursearch_grains node complains NAN particles position. Unchecking opencl neighbour search can get rid of the error though.
Technical Discussion » Particle number reduced in sliced FLIP
-
- wes_sin
- 27 posts
- Offline
I distributed a FLIP sim on the farm, I noticed that particles flow towards the slices edge and disappeared (leaking?). Two problems arise as a result of this:
1. Velocities appeared along the slices edge, thus whitewater particles could appear unintentionally.
2. Water level dropped as the simulation went on because the number of particles reduced.
I tested using one machine with no slices, there was no leaking.
Maybe I can add particles to the container to keep the amount of particle during simulation but I'd like to know is this “leaking” normal when using sliced sim? Can anyone suggest some other solutions?
Thanks in advanced.
1. Velocities appeared along the slices edge, thus whitewater particles could appear unintentionally.
2. Water level dropped as the simulation went on because the number of particles reduced.
I tested using one machine with no slices, there was no leaking.
Maybe I can add particles to the container to keep the amount of particle during simulation but I'd like to know is this “leaking” normal when using sliced sim? Can anyone suggest some other solutions?
Thanks in advanced.
Technical Discussion » how to get dop field data from constraints in H9?
-
- wes_sin
- 27 posts
- Offline
Hi,
In H8, constraint data is added as subdata under the dop object , but in H9, the constraint data is added under RelInAffectors and RelGroup, when query these two by dophassubdata(), it shows that they are not subdata. Since they aren't subdata, I failed to access any data under them.
For example, I have a wire object and I saw the following structure in the detail view: “RelInAffectors/wireSpringConstraint_applyrel5_0/Constraint/State”
inside State, there is “force” property I want to access, but I can't by using dopfield().
Can anyone give me some help…?
Wesley
In H8, constraint data is added as subdata under the dop object , but in H9, the constraint data is added under RelInAffectors and RelGroup, when query these two by dophassubdata(), it shows that they are not subdata. Since they aren't subdata, I failed to access any data under them.
For example, I have a wire object and I saw the following structure in the detail view: “RelInAffectors/wireSpringConstraint_applyrel5_0/Constraint/State”
inside State, there is “force” property I want to access, but I can't by using dopfield().
Can anyone give me some help…?
Wesley
Houdini Lounge » no $PT in DOP?
-
- wes_sin
- 27 posts
- Offline
hi, if this has been asked, i am sorry for that.
I was trying to bring a point attribute into DOP to set the strength parameter in the sbd spring constraint. The expression i used was :
point(“.:wire/Geometry”, $PT, “springstrength”, 0)
but houdini said DOP didn't know about $PT.
I think i can use nodes like copy data and stamp the values, but is there an easier way?
I was trying to bring a point attribute into DOP to set the strength parameter in the sbd spring constraint. The expression i used was :
point(“.:wire/Geometry”, $PT, “springstrength”, 0)
but houdini said DOP didn't know about $PT.
I think i can use nodes like copy data and stamp the values, but is there an easier way?
Houdini Lounge » problem in setting mutual affectors
-
- wes_sin
- 27 posts
- Offline
Hi all, i am creating a dop netwwork that require 2 levels of glue. i.e. Objects groupC glue to objects groupB, and then objects groupB glue to object groupA. Therefore, I made groupC and B mutual affectors, and groupB and A mutual affectors. No problem so far, but for some reasons I want to make sure A and C has no relationship whatsoever, so I don't want groupA and C being mutual affectors. How can I setup such a affector relationship?
I tried setting A and B mutual, B and C mutual and then merge these 2 setup with the “no change” setting. Houdini was complaining B was in multi affector groups. I've also made A and C has no collision with no colider dops .
Wesley
I tried setting A and B mutual, B and C mutual and then merge these 2 setup with the “no change” setting. Houdini was complaining B was in multi affector groups. I've also made A and C has no collision with no colider dops .
Wesley
Houdini Lounge » Trouble in understanding the copydata DOP
-
- wes_sin
- 27 posts
- Offline
Ok, I can get it work now. I should connect the the position Dop in the data field of the copydata dop instead of appending it under the rbdglueobject. Then reference the copydata dop variable by stamp() in that positon dop.
So, is it correct to say variables created by copydata should be used in a data dop, not in a object dop?
Wesley
So, is it correct to say variables created by copydata should be used in a data dop, not in a object dop?
Wesley
Houdini Lounge » Trouble in understanding the copydata DOP
-
- wes_sin
- 27 posts
- Offline
Hi all, I am trying to understand the copydata DOP. I've attached a simple test, it throws no error but it isn't working. What I want to do with the setup is to position a few RBDs up in the y-direction according to the $OBJID, before the simulation begins.
Can someone tell me what is wrong with the setup, please?
I know I don't need copydata and there are a few trivial nodes but it is just for learning :roll:
Wesley
Can someone tell me what is wrong with the setup, please?
I know I don't need copydata and there are a few trivial nodes but it is just for learning :roll:
Wesley
Houdini Lounge » find out which group a point belongs to
-
- wes_sin
- 27 posts
- Offline
hi Jeff, really thanks for your reply and the ideas. In my case, the groups are all there and they are built with the partition sop, so I can query the attribute for my point and then know which group it's in,…but I was just hoping a really quick way and thought that I might have missed such a command. Also, I was trying to build tools that can be more useful in general, so I think having a function like whichpointgroup() would be nice and more convenient. 
Houdini Lounge » find out which group a point belongs to
-
- wes_sin
- 27 posts
- Offline
Hi all, I want to find out in which point group a point is. I can't find such a command or is there a command for this?
if no, i think i'll have to loop through the existing groups and check whether a specified group contains my point…which seems to be a lot more work.
I also want to know whether i can use vex to determine what points a point group contains, i can't find a pointgrouplist equilvalent in vex.
Wesley
if no, i think i'll have to loop through the existing groups and check whether a specified group contains my point…which seems to be a lot more work.
I also want to know whether i can use vex to determine what points a point group contains, i can't find a pointgrouplist equilvalent in vex.
Wesley
Houdini Lounge » How could I delete overlapping primitives?
-
- wes_sin
- 27 posts
- Offline
ah…….yes~ How come I could forget the cookie sop, …thanks elias~!
after the cookie, then append a clean sop or (fuse sop then delete sop).
Wesley
after the cookie, then append a clean sop or (fuse sop then delete sop).
Wesley
Houdini Lounge » How could I delete overlapping primitives?
-
- wes_sin
- 27 posts
- Offline
Hi all,
As a very simple example, suppose I have 2 boxes aligned side by side (no gap between them) and merged with a merge sop, the resulting geometry will have 2 primitives overlapping each other.
How can I get rid of these overlapping primitives so that i have a hollow geometry? Basically what I want to do is to merge a few objects into one piece.
Wesley
As a very simple example, suppose I have 2 boxes aligned side by side (no gap between them) and merged with a merge sop, the resulting geometry will have 2 primitives overlapping each other.
How can I get rid of these overlapping primitives so that i have a hollow geometry? Basically what I want to do is to merge a few objects into one piece.
Wesley
Houdini Lounge » mapping chop channels to sop primitive groups?
-
- wes_sin
- 27 posts
- Offline
andrewlowell
If that doesn't foot the bill (too much stuff to export) you can do an expression in the geometry to read in chop channels of that name by the chop expression(s) and string functions via stamping.
Thx. Actually this is what I am doing now (delete -> primitive -> copy), but I noticed that houdini become quite slow as there were quite a lot of copying and channel referencing from chops. The method works fine but it's just quite slow when the no. of primitive groups is about a few hundreds. Is there another way (besides promoting each group to an object and use the export chop) which is faster and neat?
Wesley
Houdini Lounge » mapping chop channels to sop primitive groups?
-
- wes_sin
- 27 posts
- Offline
Hello, I am doing something like this:
I did a RDB sim in dop, then extracted and tweaked the rotations in chop. Now how should I applied the tweaked channels back to the primitive groups?
The channels are like this: geo_0:rx , geo_1:rx, …… geo_700:rx. I think if I expand the primitive groups to the obj level, (so that each of them is an object), then chop can recognise the object names and will distribute the channels to the correct objects. But then my scene will be flooded with a lot of objects which is not what I want. How can I manually do something like what the doptransform sop does?
many many thanks…
Wesley
I did a RDB sim in dop, then extracted and tweaked the rotations in chop. Now how should I applied the tweaked channels back to the primitive groups?
The channels are like this: geo_0:rx , geo_1:rx, …… geo_700:rx. I think if I expand the primitive groups to the obj level, (so that each of them is an object), then chop can recognise the object names and will distribute the channels to the correct objects. But then my scene will be flooded with a lot of objects which is not what I want. How can I manually do something like what the doptransform sop does?
many many thanks…
Wesley
Houdini Lounge » How to rename HDA?
-
- wes_sin
- 27 posts
- Offline
pbowmar
All you can do is Copy it, and create the new name while copying it. Then delete the old one.
Cheers,
peter B
I've ended up expanding the otl and change the name and path inside the files and dir….
Thanks Peter, copying is much easier! : P
Wesley
Houdini Lounge » How to rename HDA?
-
- wes_sin
- 27 posts
- Offline
Hello, I've created a digital asset but somehow I need to rename it for a better name, but the name field in the Type Properties window is greyed out.
I tried using the Edit Content function in Operator Type Manager, but the name always changed back to its origin name which was given when the HDA was created. The doc just mentioned it was very hard to change the name after creating the HDA.
Does anyone has a simple way to change it?
I tried using the Edit Content function in Operator Type Manager, but the name always changed back to its origin name which was given when the HDA was created. The doc just mentioned it was very hard to change the name after creating the HDA.
Does anyone has a simple way to change it?
Technical Discussion » shadow bias and Vop shadowmatte
-
- wes_sin
- 27 posts
- Offline
Is there a shadow bias control for built-in shadow options in the light node? (i mean not using vex shadow or shadowmap() funtion)
How should i connect the Vop shadowmatte so that my shadow appears in the alpha channel of the rendered pic?
Whenever i connect the output of the vop shadowmatte to the corresponding output of a vop surface shader, it just gives me the alpha of my objects, not the shadow.
Thanks in advance.
Wesley
How should i connect the Vop shadowmatte so that my shadow appears in the alpha channel of the rendered pic?
Whenever i connect the output of the vop shadowmatte to the corresponding output of a vop surface shader, it just gives me the alpha of my objects, not the shadow.
Thanks in advance.
Wesley
Technical Discussion » Fan in operation and feedback chop
-
- wes_sin
- 27 posts
- Offline
I am reading the doc of certain chops, i don't quite understand the Fan in option of the Fan Chop, any simple example to demonstrate its use?
Also, I have problem in making the feeback chop to work, I tried getting a box, keyframed its translation, and feed the t to a geometry chop followed by a feedback chop, turned on delta time. Then in sop, i get the
t back to another box by a channel sop. I was expecting the second box would travel with the first box but a frame or a second lag behind, but the result is they travelled together. Any idea to demonstrate this chop?
Thanks for any tips….!!
Wesley Sin
Also, I have problem in making the feeback chop to work, I tried getting a box, keyframed its translation, and feed the t to a geometry chop followed by a feedback chop, turned on delta time. Then in sop, i get the
t back to another box by a channel sop. I was expecting the second box would travel with the first box but a frame or a second lag behind, but the result is they travelled together. Any idea to demonstrate this chop?
Thanks for any tips….!!
Wesley Sin
Technical Discussion » display card choices
-
- wes_sin
- 27 posts
- Offline
i am thinking about getting a display card for houdini. Anyone has tried using ATI 9700pro or 9500 with houdini? Any review of ATI cards with houdini?
Technical Discussion » About PrimitiveSplit Sop
-
- wes_sin
- 27 posts
- Offline
thanks so much, Brask!!
I am not quite clear about the vm_surface attribute u mentioned, what data does this attribute store? And which OP add this attribute to primitive?
One more question…Can u explain the usage of the meta-surface weight in primitive sop?
Thanks again!!
I am not quite clear about the vm_surface attribute u mentioned, what data does this attribute store? And which OP add this attribute to primitive?
One more question…Can u explain the usage of the meta-surface weight in primitive sop?
Thanks again!!
Technical Discussion » About PrimitiveSplit Sop
-
- wes_sin
- 27 posts
- Offline
hi..
Can anyone explain how the PrimitiveSplit Sop works? I don't see any influence on the input geometry by this sop. Even after reading the document, I don't really get what this sop does.
Thanks in advance.
Wesley
Can anyone explain how the PrimitiveSplit Sop works? I don't see any influence on the input geometry by this sop. Even after reading the document, I don't really get what this sop does.
Thanks in advance.
Wesley
-
- Quick Links