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Atom last won the day on January 5

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  1. RBD issue: How can I bring them to stop?

    As Geoff suggested, your collision surface may not be setup correctly. They're probably bouncing around due to the gaps in your vdb supplied collider. Instead, model a box with some extruded thickness and supply that, not as a vdb, but as surface polygons. VDB colliders are for pyro and flip sims.
  2. Fluid-RBD interaction issue!

    Feedback scale only works with RBD Hero objects. What you can do is throw away your current RBD setup and create a new box. Click the RBD Hero object to add it to your FLIP simulation and set the feedback scale back to 1.0.
  3. RBD issue: How can I bring them to stop?

    Try using a groundplane, instead of the inside of a VDB box. Set your Sleeping Time to 0.1.
  4. The .sim files are generated by the AutoDopNetwork node. Set the timeline to Play Once, rewind and play the simulation. Click stop around 34 frames. Close Houdini. Reopen the file in Houdini and you should see a blue cache progress bar loaded with the file. Move to frame #34 and press play to continue simulating. You can see in my blue bar, here, that the previous "Checkpoint" cache is a slightly dimmer color. ap_flip_sim_continue.hiplc
  5. Houdini 20 Wishlist

    What I always wish for. We need talking characters. I want to be able to supply a voice-over file, along with a script, and have a face rig speak the lines. Expressions and blinking would be great too.
  6. Lops To Obj Lights

    With the Karma ROP available in the /out context, I wanted to conduct a few test renders to compare Lops Karma with Sops Karma. Here is a /out/karma1 render of the patchwork pig that Konstantin presented with the lights extracted from Lops. You can place this short script in a shelf tool. It tries to extract the lights from Lops and generate companion ones in Sops. # Scan the /stage context for any lights and create companion lights in /obj. # Atom 01-06-2022 import hou, re def returnValidHoudiniNodeName(passedItem): # Thanks to Graham on OdForce for this function! # Replace any illegal characters for node names here. return re.sub("[^0-9a-zA-Z\.]+", "_", passedItem) def childrenOfNode(node, filter): # Return nodes of type matching the filter (i.e. geo etc...). result = [] if node != None: for n in node.children(): t = str(n.type()) if t != None: for filter_item in filter: if (t.find(filter_item) != -1): # Filter nodes based upon passed list of strings. result.append((n.name(), t)) result += childrenOfNode(n, filter) return result def migrateLights(node_path): node_target = hou.node("/obj") if node_target != None: light_nodes = childrenOfNode(hou.node(node_path),["Lop light"]) #Other valid filters are Sop, Object, cam. for (name, type) in light_nodes: node_candidate = "%s/%s" % (node_path, name) n = hou.node(node_candidate) if n !=None: # Create the Houdini light node. light_name = returnValidHoudiniNodeName("%s" % name) node_light = hou.node("%s/%s" % ("/obj", light_name)) if node_light == None: # Create new light. node_light = node_target.createNode('hlight::2.0',light_name) else: print ("skipping creation of %s." % light_name) # Position and rotate light. node_light.parm("tx").set(n.parm("tx").eval()) node_light.parm("ty").set(n.parm("ty").eval()) node_light.parm("tz").set(n.parm("tz").eval()) node_light.parm("rx").set(n.parm("rx").eval()) node_light.parm("ry").set(n.parm("ry").eval()) node_light.parm("rz").set(n.parm("rz").eval()) # Migrate light type. lop_index = n.parm("lighttype").eval() ary_remap_index = [5,7,2,0,3,4] ary_lops_types = ["cylinder","distant","disk","point","rectangle","sphere"] ary_hlight_types = ["point","line","disk","grid","sphere","tube","geometry","distant","sun"] t = ary_hlight_types[ary_remap_index[lop_index]] node_light.parm("light_type").set(t) node_light.moveToGoodPosition() # Program starts here. path = "/stage" #path = "/obj/lopnet1" migrateLights(path)
  7. You can merge in your collision mesh and colorize it. Then use an attribute transfer to copy the collision color onto the flip particles. ap_flip_colorize_collision.hiplc
  8. On Growth and Form

    With Houdini moving to Python 3, that code no longer works on H19.0.455. I have converted the Python code to version 3, and added a slight randomness to the extrusion of each country. The new code produces a console warning, but the mesh generation still works. houdini_world_map_by_countries.zip
  9. Attach pyro sim to insane particle speeds

    Check out the last HIP file at this link. It uses a technique of an opposing field to contain density.
  10. Divide SOP to create single point in Quads

    Use another divide with Convex Polygons off and Compute Dual on. Merge that into your network after grouping those points.
  11. name & class attribute

    They are kind of the same. @name is a string, an @class is often an integer. They are both similar to @id for particles. Name is used quite often to "name" the pieces of a fracture, while class might be used to simply "group" a bunch of primitives that are not necessarily connected by any constraints. (i. e. for assigning materials or filtering primitives within a loop).
  12. Here is an example file from Houdini FX Japan that nearly eliminates the mushrooming effect. MicroSolver_Sample.hip
  13. Redshift alpha problems

    It's one of the limitations of Redshift. It only supports so many layers of texture transparency from a single point of view. Look for a parameter on the render ROP called max depth or something similar (limits..?). You may be able to increase the count. I think it does default to 6.
  14. Try using SOP Import. It looks like Scene Import is bugged.
  15. [FLIP] Unwanted noise affecting simulation

    I have seen similar reactions in a smoke simulation. There is no way to perfectly expand pyro in a spherical shape. It might just be the loss to resolution. Try setting your grid scale to 1.0. Here is an expanding flip particles at Grid 2.0. The circle falls apart after a few frames. Here is Grid 1.0. The circles remains intact longer.