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Everything posted by Tyfx567

  1. Fluids not collision with alembic geometry

    How are you colliding with your fluids? View your collision and check your spacing on your vdb. Use the Deforming Object Collision shelf tool it will set up all this for you. Then check collision by turning on collision checkbox in flip and make sure it's high res enough. If not, then turn on collision seperation and make it lower.
  2. JOB variables problem with setenv

    mathieuN, Can you help me get started in connecting python with shotgun? I would like to develop a quick access your shots browser in houdini. The browser would find that user name and limit the shots, episodes, show, based on that user name.
  3. Attached is a file to attempt to help you. I changed it a lot and if you have any questions you can ask. fracturingGeoMaskingForce_help.hipnc
  4. Alembic Points to control smoke/clouds

    You have velocity information from Softimage and it came in just fine. You can turn the icon that is highlighted on to view velocity data in houdini. Can I see a hip file as to what you are trying to achieve? A tornado sim? If you want a volume to keep the velocity information from points you can lay down a vdbfromparticle node, connect your object_merge1 (which has your alembic imported into sops) and then turn on point attributes and select "v". volume data.hipnc
  5. fill mocap volume

    Try this and tell me if that is what you want. You do all your anim on the first frame of the geo, then simply point deform after all your trails are done. Btw you helped me learn something as well with your trail sop. I thought you had to always use the add sop after trail to get lines from points but no you can do everything with trail sop. Thanks for that. Also I didn't know about the minimum position which is amazing! Also you should reduce the number of max points that I have in there. Right now it is 100 I believe you can change it to 10 and it is way faster. trail following anim.hipnc
  6. Custom Wave to Ocean

    houdini 16 now has the awesome wave by curve function in it. Check out the new ocean tools.
  7. channels in houdini can reference point attributes as long as it is only one point. simply reference the point you want to get the velcombined attribute from then use that channel number and copy and paste that channel.
  8. Re-group broken pieces into an object

    Simply take a timeshift node after your sim. On the first frame of your sim keyframe the frame parameter of that node to the end frame of your sim. On the last frame of your sim, keyframe the frame parameter of the timeshift node to the first frame. Done.
  9. Combining sim mesh with non-sim

    Could I see a hip file? Why can't you just merge them together with a merge node? On the dopnet node on object where it says *, delete that and only import your grains object. Don't allow it to get the ground collision geo from dops. Why can't you just replace your sim ground with the original ground but keep the same grain points?
  10. Adding to groups and using If Blocks

    You could use the snippet node entirely instead of the if node. You could lay down the snippet node plug the pcnumfound node into it and say if(pcnumfound > 0) { @group_hello = 1; } however this won't work since pcnumfound is only giving you the number of total points in the radius not the actual point numbers. The only way to do it and it be perfectly accurate would be to do all of your pcopens in vex in a while loop but those are more complicated especially for what you are doing. You can simply have a wrangle after your solver node in sops that says "if(@Cd.r > .1) { @group_hello = 1; } that is the less accurate way but it is perfect for what you are doing.
  11. Art Directed Wall Explosion

    I would do everything he did only I wouldn't do it in a foreach loop. Just paint more if you want more pieces added. Too slow if his geometry is heavy. Instead of painting you could simply group on the inside of a volume of a sphere or something. You can do this after you pack your geo too. You can also display an add sop that has "delete geo but keep points" and highlight your paint node which is above that add node. Your assemble node will be above your paint node. The add sop is only to see what is going on. When going into the sim you want to cut off the add node. I try to avoid for each nodes as much as possible.
  12. Variable friction

    You seem to be asking about two different things. The stick control field is a different setup than variable friction. For variable friction you can do a attrib transfer in a sop solver that transfers colors from your collision geo onto your flip sim, when the flip sim turns blue, say, then make friction increase a lot with a point wrangle? I think that would work? Or just increase friction a lot on your collision geo. A hip file would help as to why you need variable friction. There is an option in flip solver in your "volumes motion" tab under "collisions" there is stick on collision. It has a falloff field as well.
  13. Noise Control using Colour

    Do all your velocity settings on scattered points on the inside of a volume. At the very end of all your manipulation lay down a attribwrangle and make the attribute you created = vel. Then create a volume using volume sop (Can be the same one you created your points with). call it vel and make it a vector attribute. Lay down an volume from attribute node and set the attribute to vel. lay down a volume trail sop and view it and set the velocity volume to vel.* That should work. However, this method you aren't going to get a nice falloff. From the picture you will need to create a nice falloff. So be sure your points have nice falloffs to their turbulence adjustments. I'm not sure how to make the falloff adjustments with different frequences.
  14. Importing Curves from Maya

    Maybe try laying down convert node to make sure they are geo? Just shooting off ideas. Maybe try importing as fbx instead of alembic. Maybe try different file type of alembic (owaga). Delete all attributes of curves after they come in? Maybe resample the curves? Houdini still tends to be very slow reading in files for some reason.
  15. very very basic question - clouds&sand storm

    Welcome to the almost limitless, amazing, and frustrating world of Houdini. Start small projects and build up. If you are too ambitious you may never finish. Learn how to say control points by force then learn how to do pyro.. etc. Take small steps to learning a new fx. Edit = just realized this post was so old. Gonna delete it.
  16. Collision Event

    There is impact data node that can be laid down in dops but I think it automatically has it generating impact data by default.
  17. Error in the ActiveValue Sop : RBD passive object

    You probably are setting it up incorrectly. You have to be simming with rbdpackedobject as your simming method in dops for assemble to work. You can watch the houdini bullet masterclass for help. Use the shelf tools with rbdfracturedobject shelf tool to get started. If you want it active over time then lay down a sop solver in dops and do the attribute transfer of color in there. After the color is transferred then lay down a point wrangle and say i@active = @Cd.b; active has to be an integer for it to work. It can't be a float. That's what the i is for. Also don't ever use point sops they are slow. Color node is fine though. Only use vex from here on. Group nodes are slow too. Only time you need to use group node is for super accurate inside geometry grouping. Use vex by saying in attrib wrangle "if(@Cd.b > .1) { @group_name_of_group_goes_here = 1 }". active value changing over time.hipnc
  18. points stick to colour of animated texture

    Disable your attribute blur as it is really slow. Just turn up the blend width in your attribute transfer. Secondly why can't you just attribute transfer the color a second time onto the points after the first transfer? Also I am not understanding why you need points just to displace geometry anyway. Just add displacement at render time or in a attribvop. Flip comes with a rest attribute that you can enable. You can use this I think in a texture displacement map. Not sure never had to use it.
  19. VDB small / detailed objects

    You could try scaling all your geo up for your vdb calculation, doing all your sim data at that scale, then when exporting scale it back down. You could also try doing a for each node vdbing every piece of geo. Don't really like that method though. Just shooting out ideas. leaves are extremely difficult because they are so flat. Vdb's do NOT like flat geo like leaves. You must extrude them in some way to where the vdb has information. a tree branch will be fine but not leaves. Anything flat like a ground needs to be extruded in some way. Why are you trying to vdb a tree with leaves?
  20. sticking particles to the animated emitting surface

    Easy. Read up on the scatter node help section. It tells you to take a look at the output attributes. Turn on "Prim num attribute" and "Prim UVW attribute" Next freeze your scatter with a timeshift node. Freeze it at your first frame. Next lay down an attribute interpolate. Plug your first input into your scatter frozen scatter node. Then plug the second input into the mesh you scattered your points on. If your points are inside the geometry it is different but pretty much the same. You would use a point deform node for that instead. You don't need the attribute interpolate node. Only another timeshift node. Any questions don't hesitate to ask.
  21. Sourcing whitewater from points

    VDBs cannot calculate with such a thin surface. Do a extrude volume before your vdbfrompolygons node. It always has to have thickness. However that is not your main problem, I believe that the whitewater source node is supposed to be taking in dop import from a sim that was already previously done. The whitewater solver I believe needs to be pointed to your "dop import fields" node that pulls in your flip sim. (I realize you don't have a flip sim, maybe make one? Not sure what you are trying to achieve with this setup) It takes the surface and vel volumes from the flip sim along with the points you give it as well. So you making a vdb from polygons is kindof useless anyway. houdini 16 has a ocean foam node that calculates all those points for you. You don't need to do all that calculation (measuring curvature) you are doing Also your ocean is tiling. You can fix that by just having a grid as big as you want your ocean and scattering points on it with relax turned on. Put like 2000 points in the scatter node. Plug the scatter node in the first input in your ocean spectrum node. You won't get tiling anymore because the new ocean spectrum randomizes the oceans on points which is incredible!
  22. RBD active value

    You are doing it a very old method that may not work all the time anymore. It won't work if you have animating geometry if you want to do an animating fracture. The best way to get information from sops now is using a sop solver in dops. This way you also can get many more attributes from sop that you can use to drive simulation as well. The sop solver also is nice because it doesn't require the attribute transfer value to remain on the object the entire time. In my file the sphere that is passing over the box doesn't remain over all the pieces. With your method if that remained the case the pieces would not move after the sphere goes past the box pieces. With the sop solver method it allows the pieces to remain active even if the sphere goes past it. You can preview what your attribute transfer is doing in sops and then copy that attribute transfer and paste it in the sop solver in dops. active value changing over time.hipnc
  23. I have replaced the file with just a cube so you guys can still see what is going on. It's very basic. It's just a box with points at the center of each piece telling what is active and what is not active. however when I put this expression: point("/obj/Angel/AC", groupbyvals("/obj/Angel/AC", D_POINT, "name", $OBJNAME), "ACTIVE", 0) in the active value DOP that I got from another dude on a forum on here, that expression doesn't work. Can someone please tell me what I am doing wrong here? This is for a demo reel project so I am on a time crunch..that's why I'm posting this. Thanks so much!! Angel_Destruction_3.hip
  24. Hey Wen, actually, this post is extremely old and I figured out how to do it much more efficiently since then. I made a sample file for you to learn from. I've learned a whole lot since then and it makes me feel stupid that I did it the hard way. Notice that I have "overwrite attributes from sop" checked on in dops in the packed object. Watch the "bullet masterclass" show to learn more techniques. Also watch "wrangle workshop" on vimeo if you don't know vex. If you need help don't hesitate to ask. I enjoy helping others when I know things Active_showing.hip
  25. Hey guys, I am wanting to loop over points and take say some random attribute from 0-10 let's say on the points. I want to take that attribute and for every point store the previous attribute of the previous point it is looping through and append it to the list. example: num numarray point 0 = 2 [2] point 1 = 4 [2,4] I attempted to do this in vex and it already is looping over the points so you can't do an append as far as I am aware because you can't look at previous point. If you can please let me know With python you can, but since I am so new to python I can't even get arrays working in python I create attribute with "attribute create" node before python node so I get [] empty array on the point attribute. I call it "emptyarray". then I try this node = hou.pwd() geo = node.geometry() points = hou.Geometry.points(geo) testarray = [2,5] #test #readA = hou.Geometry.findPointAttrib(geo, "emptyarray") for i in points: hou.Point.setAttribValue(i, 'emptyarray', testarray) But it does nothing but error out