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Technical Discussion » how to create "packed full transform" in packed object instead of ever-changing bounding box?
- fengshuochange
- 16 posts
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Here is the houdini file about that method.
Edited by fengshuochange - Sept. 3, 2019 07:08:32
Technical Discussion » how to create "packed full transform" in packed object instead of ever-changing bounding box?
- fengshuochange
- 16 posts
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Ok…I replied myself 2 times…But later found I was using another account.
Here is the answer.
I heard from other people that the “packed full transform” is actually for object instead geometry.
I didn't get the “packed full transform” as I was applying transform animation to geometry and pack the geometry instead of the object.
Here is the solution to get transform information(rotation especially) from a packed geo. It maybe useful when u want the transform information from a cached RBD object. I use this way to replace a thick RBD, which is easy for simulation, with a thinner one(because it looks better).
Choose the packed object, unpack - use Timeshift to get the geo at first frame - use ExtractTransform, the Timeshift one into the first input and the unpacked geometry for the second input - done!
Here is the answer.
I heard from other people that the “packed full transform” is actually for object instead geometry.
I didn't get the “packed full transform” as I was applying transform animation to geometry and pack the geometry instead of the object.
Here is the solution to get transform information(rotation especially) from a packed geo. It maybe useful when u want the transform information from a cached RBD object. I use this way to replace a thick RBD, which is easy for simulation, with a thinner one(because it looks better).
Choose the packed object, unpack - use Timeshift to get the geo at first frame - use ExtractTransform, the Timeshift one into the first input and the unpacked geometry for the second input - done!
Edited by fengshuochange - Sept. 3, 2019 07:13:20
Technical Discussion » how to create "packed full transform" in packed object instead of ever-changing bounding box?
- fengshuochange
- 16 posts
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Hi, I am trying to get the rotation information from an alembic file exported by houdini.
I found that I should go and look for an attribute called “packed full transform”. However that attribute is not changing at all.
Later I found every time I use Pack node, I can only get information of an ever-changing bounding box but never the “packed full transform”.
So is there any way to pack geometry with “packed full transform”. Or is there a way to get the rotation information from those changing bounding box information?
Thx~
I found that I should go and look for an attribute called “packed full transform”. However that attribute is not changing at all.
Later I found every time I use Pack node, I can only get information of an ever-changing bounding box but never the “packed full transform”.
So is there any way to pack geometry with “packed full transform”. Or is there a way to get the rotation information from those changing bounding box information?
Thx~
Technical Discussion » Does feedback scale in flip solver bring in the correct buoyancy?
- fengshuochange
- 16 posts
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Hi Dave.
Sry for the delay.
Here is the .hip file.
The problem about Pop Float by Volume last time does not exist. Maybe last time I made some mistake on connecting nodes.
But here is a new one, the Pop Float by Volume works pretty good with Pop Object while interacting with Flip object while not so good
with RBD Packed Object.
I find a way to solve this, which is to import the Flip Object into SOP and create volume from that, then import it back to DOP. But the problem is that takes too much time.
And the limitation of Gas Limit Particles is also included.
Thx so much for the advice and help.
Sry for the delay.
Here is the .hip file.
The problem about Pop Float by Volume last time does not exist. Maybe last time I made some mistake on connecting nodes.
But here is a new one, the Pop Float by Volume works pretty good with Pop Object while interacting with Flip object while not so good
with RBD Packed Object.
I find a way to solve this, which is to import the Flip Object into SOP and create volume from that, then import it back to DOP. But the problem is that takes too much time.
And the limitation of Gas Limit Particles is also included.
Thx so much for the advice and help.
Technical Discussion » Does feedback scale in flip solver bring in the correct buoyancy?
- fengshuochange
- 16 posts
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Just tested the “POP Float By Volumes”.
That's a better version for bouyancy.
The problem is, as the RBD does not have energy loss, it will bounce up and down at the boundary instead of floating on the surface like a boat.. I tried to use “POP Drag” but its move is stiff.
If I use the “Gas Limit Particles”, the movement is pretty good. And RBD could also be constrained at the boundary. However “Gas Limit Particles” could only use the “bounding box” of a volume, instead of the volume shape.
So…haven't found a perfect way.
That's a better version for bouyancy.
The problem is, as the RBD does not have energy loss, it will bounce up and down at the boundary instead of floating on the surface like a boat.. I tried to use “POP Drag” but its move is stiff.
If I use the “Gas Limit Particles”, the movement is pretty good. And RBD could also be constrained at the boundary. However “Gas Limit Particles” could only use the “bounding box” of a volume, instead of the volume shape.
So…haven't found a perfect way.
Edited by fengshuochange - Aug. 22, 2019 06:10:26
Technical Discussion » Does feedback scale in flip solver bring in the correct buoyancy?
- fengshuochange
- 16 posts
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Thx Dave.
I am using the Buoyancy Force now. It turns out to be extremely difficult to find a balanced parameter combination. And it's also pretty unstable.(If I put an RBD inside the flip object, it may float and fall back into flip and never float again)
Since I am trying to achieve the effect of bubbles in water, I am now using a large buoyancy force with Gas Limit Particle to limit the RBD on the surface.
I am using the Buoyancy Force now. It turns out to be extremely difficult to find a balanced parameter combination. And it's also pretty unstable.(If I put an RBD inside the flip object, it may float and fall back into flip and never float again)
Since I am trying to achieve the effect of bubbles in water, I am now using a large buoyancy force with Gas Limit Particle to limit the RBD on the surface.
Technical Discussion » stamp conflict in dop?
- fengshuochange
- 16 posts
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Long story short, this is in sop solver and I am trying to use the copy node to do stamp parameter from point on the right, which is from the dop geometry import. After the sop solver is an RBD solver.
The purpose is to use the copy stamp to get the pscale value from point on the right and resize the dop geometry by coping the original geometry to the point.
The problem is, when I uncheck the “stamp input”, the simulation runs well. The size is changing and the RBD simulation is good.
However if I check the “stamp input”, the RBD simply does not work even if I didn't stamp any data.
I checked about the RBD packed object node and found that in the SOP Geometry node there are also stamps. As the geometry is created and the data is also ready to be read (in the “create_or_overwrite_attributes” node, they have been created), I am wondering if the problem is cause by the conflict of stamp.
I did found a way to solve it, which is to use @pscale directly. But I am still confused about this problem (exactly how it is caused) and curious about how I can fix the “conflict”.
Thx for any ideas.
The purpose is to use the copy stamp to get the pscale value from point on the right and resize the dop geometry by coping the original geometry to the point.
The problem is, when I uncheck the “stamp input”, the simulation runs well. The size is changing and the RBD simulation is good.
However if I check the “stamp input”, the RBD simply does not work even if I didn't stamp any data.
I checked about the RBD packed object node and found that in the SOP Geometry node there are also stamps. As the geometry is created and the data is also ready to be read (in the “create_or_overwrite_attributes” node, they have been created), I am wondering if the problem is cause by the conflict of stamp.
I did found a way to solve it, which is to use @pscale directly. But I am still confused about this problem (exactly how it is caused) and curious about how I can fix the “conflict”.
Thx for any ideas.
Technical Discussion » Does feedback scale in flip solver bring in the correct buoyancy?
- fengshuochange
- 16 posts
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I think I may understand the feedback scale in a wrong way.
That parameter decide the reverse force while the fluid hit collision.
To get the buoyancy force, I need to use buoyancy node.
That parameter decide the reverse force while the fluid hit collision.
To get the buoyancy force, I need to use buoyancy node.
Technical Discussion » Does feedback scale in flip solver bring in the correct buoyancy?
- fengshuochange
- 16 posts
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I was creating a fluid simulation with rbd object.
I set the density of flip object and rbd object the same and set the feedback scale in flip solver to 1.
The rbd object is put inside the flip object and as the both objects share the same density, the rbd object should not moves upwards. However it does.
So I am not sure what goes wrong.
Thx for any help~
I set the density of flip object and rbd object the same and set the feedback scale in flip solver to 1.
The rbd object is put inside the flip object and as the both objects share the same density, the rbd object should not moves upwards. However it does.
So I am not sure what goes wrong.
Thx for any help~
Technical Discussion » Can we declare a custom function before the main function and defining it after main function in houdini?
- fengshuochange
- 16 posts
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jsmack
You can in .vfl VEX source files. You need to manually compile them though with the vcc commandline tool. If you are talking about a ‘wrangle’ node, you don't actually have access to the main function. The entirety of the source is a void function called in the main function.
You can also define nodes in C++ using the HDK and compiling them, which would follow the form you describe.
thx~
Technical Discussion » how does "piece attribute" in Tetrahedralize node work?
- fengshuochange
- 16 posts
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I am trying to understand the parameters in Tetrahedralize node. However the “piece attribute” confuses me a lot.
It works out fine by default. But when I add a Name node to the geo and set batch to “attribute”, it keeps telling me “nothing to tetrahedralize”.
I don't know why it happens. Thx for any help.
It works out fine by default. But when I add a Name node to the geo and set batch to “attribute”, it keeps telling me “nothing to tetrahedralize”.
I don't know why it happens. Thx for any help.
Technical Discussion » Can we declare a custom function before the main function and defining it after main function in houdini?
- fengshuochange
- 16 posts
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in C, I can write something like:
int sum(int a, int b);
void main()
{
sum(1, 2);
}
sum(int a, int b)
{
return a + b;
}
I can see the main() much easier in this way by putting all the custom functions behind the main(). However I don't know how to do that in houdini.
Is there any way to achieve that?
thx~
int sum(int a, int b);
void main()
{
sum(1, 2);
}
sum(int a, int b)
{
return a + b;
}
I can see the main() much easier in this way by putting all the custom functions behind the main(). However I don't know how to do that in houdini.
Is there any way to achieve that?
thx~
Technical Discussion » Print node in Mat not working well
- fengshuochange
- 16 posts
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Thx mrCatfish
I did link the print to a null node and check the “output text to console”.
But it still doesn't work.
And in another topic I posted(it's my first time posting topic…so I posted the same topic twice…), someone told me the file that doesn't work for me works fine with him…
So…I don't know…
I did link the print to a null node and check the “output text to console”.
But it still doesn't work.
And in another topic I posted(it's my first time posting topic…so I posted the same topic twice…), someone told me the file that doesn't work for me works fine with him…
So…I don't know…
Edited by fengshuochange - May 12, 2019 21:37:35
Technical Discussion » problem about "print" node in mat
- fengshuochange
- 16 posts
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bonsak
Your B.hip works fine for me with Indie 17.5.173 on w10
-b
well…guess that means it's just a problem with my computer or software version T T
Technical Discussion » problem about "print" node in mat
- fengshuochange
- 16 posts
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The problem is “print” node in Mat could not return the value(the console will not pop up).
Here I have 2 files which have exactly the same nodes.
The file A is from the Internet where other people use “print” node and it works well. I delete all his nodes and create some other nodes to make things easier to understand.
The “print” node could return the right value in console while rendering.
So I create a file B and do exactly the same thing. But the console just won't pop up when I start render.
By the way, the console will not pop up either if I use non-commercial houdini to open file A.
I really have no idea about why that happens.
Thanks for any clue.
Here I have 2 files which have exactly the same nodes.
The file A is from the Internet where other people use “print” node and it works well. I delete all his nodes and create some other nodes to make things easier to understand.
The “print” node could return the right value in console while rendering.
So I create a file B and do exactly the same thing. But the console just won't pop up when I start render.
By the way, the console will not pop up either if I use non-commercial houdini to open file A.
I really have no idea about why that happens.
Thanks for any clue.
Edited by fengshuochange - May 11, 2019 02:54:12
Technical Discussion » Print node in Mat not working well
- fengshuochange
- 16 posts
- Offline
The problem is “print” node in Mat could not return the value(the console will not pop up).
Here I have 2 file which have exactly the same nodes.
The file A is from the Internet where other people have “print” node and it works well. I delete all his nodes and create some other nodes to make things easier to understand.
The “print” node could return the right value in console while rendering.
So I create a file B and do exactly the same thing. But the console just won't pop up when I start render.
By the way, the console will not pop up either if I use non-commercial houdini to open file A.
I really have no idea about why that happens.
Thanks for any clue.
Here I have 2 file which have exactly the same nodes.
The file A is from the Internet where other people have “print” node and it works well. I delete all his nodes and create some other nodes to make things easier to understand.
The “print” node could return the right value in console while rendering.
So I create a file B and do exactly the same thing. But the console just won't pop up when I start render.
By the way, the console will not pop up either if I use non-commercial houdini to open file A.
I really have no idea about why that happens.
Thanks for any clue.
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