Found 39 posts.
Search results Show results as topic list.
Technical Discussion » How to model snowH dynamics?
- catchyid
- 39 posts
- Offline
Technical Discussion » How to model snowH dynamics?
- catchyid
- 39 posts
- Offline
Hey guys!
I was watching “Frozen”, and there are lots of snow dynamics scenes where horses run on snow and the entire volume of the snow changes in response to their legs movement. You can also see trails, lumps of snow accumulating, etc. I am thinking: how did they simulate these snow effects? In Houdini, I have not tested “Grain” solvers/tool-shelf, but I think this would be the closest way to do snow effects like the one I've mentioned?
Thanks
I was watching “Frozen”, and there are lots of snow dynamics scenes where horses run on snow and the entire volume of the snow changes in response to their legs movement. You can also see trails, lumps of snow accumulating, etc. I am thinking: how did they simulate these snow effects? In Houdini, I have not tested “Grain” solvers/tool-shelf, but I think this would be the closest way to do snow effects like the one I've mentioned?
Thanks
Technical Discussion » Dust Simulation Question
- catchyid
- 39 posts
- Offline
Technical Discussion » Dust Simulation Question
- catchyid
- 39 posts
- Offline
Hi,
This is a very general question and I am looking for some ideas/hints/directions.
In summary, I need to simulate what happens when horses run in desert, i.e. at each foot step ground particles rise up then fall slowly (maybe with some disturbance too). I am not sure what the right way to simulate this effect is: this is not particles simulation because the effect should look like a contentious volume and not particles, however it's not also smoke simulation because particles might fall quickly on the ground, i.e. they won't suspend too much in the air flow/turbulence created. I “think”, maybe a particle simulation should be created and use it as a smoke source, but again, the smoke simulation must be configured to fall down quickly?!
BTW, the same “effect” occurs when you drop a heavy box on the floor, when car wheels go very fast, etc.
Any ideas will be appreciated
This is a very general question and I am looking for some ideas/hints/directions.
In summary, I need to simulate what happens when horses run in desert, i.e. at each foot step ground particles rise up then fall slowly (maybe with some disturbance too). I am not sure what the right way to simulate this effect is: this is not particles simulation because the effect should look like a contentious volume and not particles, however it's not also smoke simulation because particles might fall quickly on the ground, i.e. they won't suspend too much in the air flow/turbulence created. I “think”, maybe a particle simulation should be created and use it as a smoke source, but again, the smoke simulation must be configured to fall down quickly?!
BTW, the same “effect” occurs when you drop a heavy box on the floor, when car wheels go very fast, etc.
Any ideas will be appreciated
Technical Discussion » Two Pyro Questions
- catchyid
- 39 posts
- Offline
Okay, so to make sure I understand you correctly:
> Temperature is controlled by artist (i.e. an artist can paint temperature profile in the grid), also, Temperature could be adjusted by noise (disturbance), finally it's part of the physical simulation parameters (i.e. density moves from high to low temperature).
> Heat is where there is enough fuel and temperature is high enough (another way to say it, Heat is the intersection of fuel and temperature fields). It could be that there is high temperature but no fuel, and hence no Heat or burn occurs, and that's why high temperature is not enough to detect “burn”
Thank you
> Temperature is controlled by artist (i.e. an artist can paint temperature profile in the grid), also, Temperature could be adjusted by noise (disturbance), finally it's part of the physical simulation parameters (i.e. density moves from high to low temperature).
> Heat is where there is enough fuel and temperature is high enough (another way to say it, Heat is the intersection of fuel and temperature fields). It could be that there is high temperature but no fuel, and hence no Heat or burn occurs, and that's why high temperature is not enough to detect “burn”
Thank you
Technical Discussion » Two Pyro Questions
- catchyid
- 39 posts
- Offline
Okay, first part is answered, i.e. I still have fuel in the system due to fuel efficiency …
second question is still not answered …
second question is still not answered …
Technical Discussion » Two Pyro Questions
- catchyid
- 39 posts
- Offline
Hi,
I have a basic pyro simulation (a variation of fireball setup from shelf). I have the following questions regarding heat and temperature fields:
1- Although no fuel is injected in the grid, temperature is increasing? If there is no fuel in the grid, why temperature keeps increasing? I set cooling rate to 1.0 and I still see temperature going up and down (according to the documentation 1.0 should remove all temperature!)
2- What is the difference between heat and temperature? I know Mantra renders “heat” as fire, but what makes it different? Why not just say and temperature > 10 will be rendered as fire or black body?
Thanks,
Edited by catchyid - April 17, 2017 12:04:25
Technical Discussion » How to make an inner OBJ node "Transformation" the default "Transform" tool of a HDA?
- catchyid
- 39 posts
- Offline
WOW I am impressed… Did I miss this info in the Documentation? Anyways, Thaaaanks a lot….
Technical Discussion » How to make an inner OBJ node "Transformation" the default "Transform" tool of a HDA?
- catchyid
- 39 posts
- Offline
Hi,
I have a digital asset (HDA) that has three OBJ nodes A,B and C. The HDA itself has no meaningful transformation -it should be set to identity. Only Object C has a meaningful transformation.
I want to do the following: When a user selects the HDA node, he gets the transformation handlers of the inner Object node C, such that if he translates in X direction he actually translates Object C.
In the attached Image, Pyro_Import is Object C, and I want Pyro_Import transformation handles appear when the use select the digital asset. Currently when the user select the Digital Asset, no handles appear …
I am not sure how to do that, if anyone has some pointers I would really appreciate it
I have a digital asset (HDA) that has three OBJ nodes A,B and C. The HDA itself has no meaningful transformation -it should be set to identity. Only Object C has a meaningful transformation.
I want to do the following: When a user selects the HDA node, he gets the transformation handlers of the inner Object node C, such that if he translates in X direction he actually translates Object C.
In the attached Image, Pyro_Import is Object C, and I want Pyro_Import transformation handles appear when the use select the digital asset. Currently when the user select the Digital Asset, no handles appear …
I am not sure how to do that, if anyone has some pointers I would really appreciate it
Technical Discussion » How to know the name the instance of the asset that OnCreated() is associated with?
- catchyid
- 39 posts
- Offline
Technical Discussion » How to know the name the instance of the asset that OnCreated() is associated with?
- catchyid
- 39 posts
- Offline
Thanks Just another question, I could not find in the documentation the entire content of kwargs dictionary, I found some keys like ‘node’, ‘parm’, ‘old_name’ but I got these names after watching an online tutorial
My question: does the content of kwargs change with context? Is there is a central place to know its content in each context? I know ‘kwargs’ is a python thing but I totally new to python…
Thanks,
My question: does the content of kwargs change with context? Is there is a central place to know its content in each context? I know ‘kwargs’ is a python thing but I totally new to python…
Thanks,
Technical Discussion » How to know the name the instance of the asset that OnCreated() is associated with?
- catchyid
- 39 posts
- Offline
Hi,
When I create a digital asset, I go to Scripts->OnCreated() method and write some python script to change some parameters in the newly created digital asset, HOWEVER, I don't know the name of the asset, hence I don't know the path to any node inside the digital asset? When I type hou.pwd(), I get “obj”…
Thanks,
When I create a digital asset, I go to Scripts->OnCreated() method and write some python script to change some parameters in the newly created digital asset, HOWEVER, I don't know the name of the asset, hence I don't know the path to any node inside the digital asset? When I type hou.pwd(), I get “obj”…
Thanks,
Technical Discussion » How to save a "Default" kay-frame animation with a digital asset?
- catchyid
- 39 posts
- Offline
Thanks Tomas! This is exactly what I want.
Thanks…
Thanks…
Edited by catchyid - April 12, 2017 14:48:07
Technical Discussion » How to save a "Default" kay-frame animation with a digital asset?
- catchyid
- 39 posts
- Offline
Hi,
I've created a digital asset for an explosion, it simply hides the pyro simulation network and exposes simple parameters such as buoyancy, smoke dissipation. I want to allow the asset users customize some animation curves such as “gasrelease” (which is defined in the pyro solver). This seems problematic because:
a-If I keep the animation inside the digital asset network, then this animation curve is considered part of the digital asset and it will be locked by default. The only way to edit the curve would be to unlock the digital asset and save the file, but this is bad because users might save the new asset definition and replace the default one, plus it's not practical to ask users to unlock the asset each time they want to edit it!
b-If I keep the animation as an external new parameter (i.e. use the type interface to add a new parameter and add the animation curve to it), for some unknown reasons it won't get saved as part of the digital asset definition! i.e. even If create a new parameter and create some key frames then save the asset type, the next time I create a new instance of the asset the animation curve will be lost, i.e. will be constant value…
Okay, I am not sure what I am doing wrong, but this seems like an easy thing to do but yet I cannot accomplish! All, what I want to do is to create an initial animation curve for the gas released parameters and then allow users to change it if they wish?
Thanks
I've created a digital asset for an explosion, it simply hides the pyro simulation network and exposes simple parameters such as buoyancy, smoke dissipation. I want to allow the asset users customize some animation curves such as “gasrelease” (which is defined in the pyro solver). This seems problematic because:
a-If I keep the animation inside the digital asset network, then this animation curve is considered part of the digital asset and it will be locked by default. The only way to edit the curve would be to unlock the digital asset and save the file, but this is bad because users might save the new asset definition and replace the default one, plus it's not practical to ask users to unlock the asset each time they want to edit it!
b-If I keep the animation as an external new parameter (i.e. use the type interface to add a new parameter and add the animation curve to it), for some unknown reasons it won't get saved as part of the digital asset definition! i.e. even If create a new parameter and create some key frames then save the asset type, the next time I create a new instance of the asset the animation curve will be lost, i.e. will be constant value…
Okay, I am not sure what I am doing wrong, but this seems like an easy thing to do but yet I cannot accomplish! All, what I want to do is to create an initial animation curve for the gas released parameters and then allow users to change it if they wish?
Thanks
Technical Discussion » [Solved] Animated Parameters keyframes lost when exported in a Digital Asset?!
- catchyid
- 39 posts
- Offline
— Okay, I was using promote parameter the wrong way…I should not promote in the first place, instead use the default to store a pointer to the animated channel
Hi,
Let's say we have a sphere (i.e. /obj/sphere_geo/sphere_sop), and we create a Digital Asset out of it. If I promote the sphere's uniform scale to the digital asset interface, then houdini will create another parameter (scale2) and link the original inner scale to it (i.e. the inner uniform scale would be ch(“../scale2”)). So far is good!
HOWEVER, if the inner uniform scale has some initial keyfames, then when it gets promoted those keyframes will be lost! If these keyframes contain some initial “default” animation, then they would be lost when one creates an instance of the digital asset?! Note that if the uniform scale has just a single default value, it will be copied as the default value in the promoted digital asset parameter, however if it has keyframe animation it will be lost?!
My question, how to keep these keyframes in the digital asset, such that an instantiated digital asset will have an initial animation and the user is allowed to change it if he wishes?
Thanks
Hi,
Let's say we have a sphere (i.e. /obj/sphere_geo/sphere_sop), and we create a Digital Asset out of it. If I promote the sphere's uniform scale to the digital asset interface, then houdini will create another parameter (scale2) and link the original inner scale to it (i.e. the inner uniform scale would be ch(“../scale2”)). So far is good!
HOWEVER, if the inner uniform scale has some initial keyfames, then when it gets promoted those keyframes will be lost! If these keyframes contain some initial “default” animation, then they would be lost when one creates an instance of the digital asset?! Note that if the uniform scale has just a single default value, it will be copied as the default value in the promoted digital asset parameter, however if it has keyframe animation it will be lost?!
My question, how to keep these keyframes in the digital asset, such that an instantiated digital asset will have an initial animation and the user is allowed to change it if he wishes?
Thanks
Edited by catchyid - April 10, 2017 15:22:47
Technical Discussion » VDB questions
- catchyid
- 39 posts
- Offline
Just an update, one other user on odforce suggested that before converting the pyro simulation into vdb, I can just use expressions volumemin/volumemax to read min/max values and it did work… just wanted to share
Technical Discussion » VDB questions
- catchyid
- 39 posts
- Offline
Technical Discussion » VDB questions
- catchyid
- 39 posts
- Offline
Alright…Thanks for your help I don't really need to see ALL values I just wanted to know min/max values so I can fine tune shading parameters, but will test your method as it should be enough… Once more, thanks for your help
Technical Discussion » VDB questions
- catchyid
- 39 posts
- Offline
Hi,
I am doing some pyro simulation, exporting result as VDB. I have the following two questions:
1) Is it possible to see the max/min range for temperature and density fields? Even more, can I see the entire range of values in a list view just as we view point attributes in the geometry spreadsheet? I want to do so because I am rendering in an external renderer and it will help see the values of density/temperature so I can fine tune the renderer shading parameters…
2) I am not sure if this is even valid for not, but Houdini produces one VDB per frame (i.e. when I use ROP output driver, it stores file.01.vdb, file.02.vdb or in general file.$F.vdb). Now, my question is there such a thing to store ALL vdb files in one big file? i.e. one file that has vdb in different time frames? I am not sure if this exists or not, but I am just doing some basic research…
Thanks,
I am doing some pyro simulation, exporting result as VDB. I have the following two questions:
1) Is it possible to see the max/min range for temperature and density fields? Even more, can I see the entire range of values in a list view just as we view point attributes in the geometry spreadsheet? I want to do so because I am rendering in an external renderer and it will help see the values of density/temperature so I can fine tune the renderer shading parameters…
2) I am not sure if this is even valid for not, but Houdini produces one VDB per frame (i.e. when I use ROP output driver, it stores file.01.vdb, file.02.vdb or in general file.$F.vdb). Now, my question is there such a thing to store ALL vdb files in one big file? i.e. one file that has vdb in different time frames? I am not sure if this exists or not, but I am just doing some basic research…
Thanks,
-
- Quick Links