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About Mokiki

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  1. This I am pretty sure has an easy solution but I didn't manage to figure it out myself. I did a simple rdb grain sim and want to swap/copy the geo I use for rendering onto the points I fetch from simulation. My current method is to use a test object I want to copy with a copytopoints that is connected to a dopimport node. (Set to: Fetch packed geometry from dop network + display as centroid). Now this works for the most part. My test object is copied onto the points and follows the rotation and movement. But the issue I am having is that it doesn't take into account the initial rotation value and that the test object is not lining up with all of my simulation geo. Hopefully what I am after at least makes some sense with the file provided. replace_grain_odforce_upload.hiplc
  2. Damn would have thought its possible since all the different velocity etc. attributes are present. But guess I have to redo the sim then. Thanks for the answer though. :) *Edit* So the sim files are basically large files containing all simulated frames? Just to be on the save side I take it I activate the checkpoint option on the dopnetwork. Set my checkpoint intervals, the checkpoint trail length and that should be it? How would I then resume the sim base on a sim file if the need arises?
  3. I have read a few conflicting information regarding this, so I want to ask myself. Is it possible to resume a flip sim based on the bgeo.sc. files? And if so how? I tried the initial data tab inside the fluid object according to the help file but with not much success.
  4. Thank you. You definitely gave me a lot of information to work with. I really appreciate it.
  5. Huge thank you for your help Tomas. Since my vex knowledge is pretty much zero. (Will study your examples once I am back at my workstation) But just for my understanding. Is the disadvantage of the live setup that it's computationally more expensive? Or that it might switch the points it already placed into nearby groups again when the 4 streams collide with each other? Sorry for asking really basic questions. I think I avoided using the solver because in my previous tests I had problems with changing point counts. But that was when I tried to make groups by bounding box stick via solver and get my animation back by copying the point positions which resulted in weird jittering, while it worked completely fine in non changing point count situations. To answer your question I had a small discussion with the artist last week. And from what he told me he is using a few different scripts to get a certain look for the fluid in realflow. Downside of said scripts is that the fluid tends to get unstable if they affect multiple emitters so all emitters are injected into 1 container. All newly spawned particles have the settings of the container. The different viscosity values were just something I did to get some quick tests done. But I agree it's too much of a hassle for the effect I am supposed to do. The goal is just to mix the point colors once the particle groups collide with each other and get some quick and dirty paint color mix effect. On the plus side I learned a lot during the last week thanks to this community. It seems though that I have to give vex a closer look sooner than anticipated.
  6. Hello Tomas, thanks for taking the time to help. I cleaned up a file to hopefully make it clear what I am trying to do. I also included the first few frames from the particle sim. Explanation: The file shows 4 particle spawn locations and each location is basically represented by 1 group. Each one has a different color which I later need to work with. The problem is that during the sim new particles are created to fill the holes, which don't fulfill my grouping requirements. In this example it is a different viscosity value but in the real work file it's just the emitter location. So I want those newly created particles to join the closest group around them and stay in the group they joined. The biggest problem is that the simulation that I have to manipulate wasn't done by me and I have no way to distinguish between the different particle groups except their emitter location. All particles are in 1 alembic sequence and have the same parameters. So I don't have any attributes to mark like in the example I uploaded. Luckily I already solved that problem, but I didn't take into account the particles that spawn within the fluid to fix holes, so they can only distinguished by their spawn location. (e.g they didn't originate where the others came from) Cheers, Oliver odforce_adding_to_nearby_groups.rar
  7. *Edit* Sorry! I just noticed I posted this in the wrong forum section. Could one of the mods please move it? This might be pretty simple but I have a hard time wrapping my head around adding points to groups based on a specific requirement. I have 4 point groups and amidst those groups new points are being generated that don't belong to any of the groups. What I want to do is having the points that are being generated check for the closest group they find, join that group and stay in it. Currently trying to build this system in a pointvop but I have a hard time understanding the logic I have to use. Even the first step of identifying the points to work on is a problem for me. I can easily check with "InGroup" for those points not in any of the groups and get a bool statement out of that but it is not really clear to me how I can reverse this information and get the pointnumber of said points. Hopefully somebody can help me and point me in the right direction. Cheers!
  8. simple color mix via pointvop

    I have an already finished fluid sim done in realflow I'd like to manipulate in Houdini. What I want to do is a very simple color mix where the two particle systems touch each other. I thought this would be pretty straight forward but I have a hard time grasping the correct use of the nodes used in the pointvop. I think I understand the logic I have to use: Have the points compare their positions to each other within a radius have the found points spit out a true condition which allows said points to change color via the color mix node. The end goal would be to maybe add a third/fourth color to the mix and grow the color spread over time but since I am still struggling with the basics I'll keep that on hold for now. So if somebody could give me any advice I'd really appreciate it. *Edit* Figured the first part out. Got a basic two color mix working. Needed a much simpler setup than I was thinking of but still this way of working definitely needs some getting used to. Especially in relation to all the different data types being produced.
  9. RDB Question: Gravitational Pull

    I managed to get around the the issue at least in my case by simply importing my rbd objects via dop import and just copying my my initial geo on their position and using that in the point vop driving the ripple solver. It's probably not the most elegant solution but it does it's job for now.
  10. RDB Question: Gravitational Pull

    Yep it's sorted out everything is working now. I just was curious about why non packed geometry doesn't work in your example. So packed geo allows you to use pop forces in rigid body sims and non packed geo does not. Is that correct? Only reason I bring this up is because I was doing an effect with the ripple solver + custom geometry reacting to an rbd sim and in turn having the rbd sim react to the ripples created. Almost giving it this softbody like look in a way and at some point I noticed I didn't get the back and forth reaction to work until I used non packed geo. I think the error is in my point vop setup. It has trouble reading the point data from the surfaces of the packed objects to drive the deformation for the ripple solver. My goal was to combine that effect with the one mentioned in this thread. Will definitely have to study the help file some more. Nonetheless really appreciate the help.
  11. RDB Question: Gravitational Pull

    I will now lower my head in shame from here on onward. No idea why I didn't dive inside the geometry vop. Thank you Sepu for pointing it out.
  12. RDB Question: Gravitational Pull

    Thank you David and Vitor for the tips! Really appreciate it. I took a look at your file David and this is pretty much what I tried to achieve. But I still ran into 1 issue that I don't really understand. When trying to rebuild your setup manually I run don't get any simulation going. My rigid body doesn't want to move at all. When I copy your dopnet into my scene the simulation works. I went through each node and checked for differences in the various tabs but I didn't find anything. If you could take a quick look at the attached scene that would be great. (I already know that it is going be something completely obvious ) Oh there was another thing I got curious about. When switching rbdpackedobject for rdbobject and not creating packed geometry in your setup, it doesn't seem to work anymore. Is there any specific reason for this? gravitational_pull_upload.hipnc
  13. RDB Question: Gravitational Pull

    I am new to Houdini so I apologize if this is common knowledge. I tried the search function but haven't found what I was looking for. Currently I am trying to point my gravity towards the surface normals of my collision geometry. The simplest example would be having a tiny planet where your objects(Spheres) are affected by wind; bounces etc. but are not supposed to completely fly off the planet, more like roll along the surface. Hope I didn't make it sound too confusing. It would be great if somebody could point me in the right direction. Big thanks in advance.