tagosaku

uh, that's good to know there are step limitation! Then, I tried VDB advect. It's working well. but calculation gets heavier and heavier when setting time step more and/or faster vel. I wanted to try this method because I heard one of VFX companies have a VEX/VOP based fog animation, instead of using sop-solver or dopnetwork The system is not for replacement with regular fog sim, but it works for a simple Background-quality fog. And I assume that should create unique fog shape and unique motion, unlike filling out an entire box boundary volume, unlike simple linear straight offset animation.

Hi, I am trying to understand advectByVolumes node. Basically I create custom vel field and animate density by advection. When increasing timestep, density moves more, but there looks a certain distance limitation, and density does not move further anymore. I wonder what's a logic and a solution for that, instead of using sop-solver, in order to continue to proceed density animation. advectTest.hip

thank you so much for all our tips. Legal agreement and violation things are tricky. And using python with date and switch is a great idea!! In general, most houdini artists simply bring own tools to use for own shots, and other artists and production won't pay attention so much about how great a tool would be. HR says Houdini artists almost never sign up for own pre-invention uses, but sometimes pipeline artists do that.

hi, I am wondering if we can set an expire-date for HDA or blackbox? Let's say a freelancer works a project at a company for one year with bring his own HDA of a custom solver. Then that HDA will be expired and won't work any more after 1 year.

yes, that's true. Question would be how to attach leaves/fruits on tips of branches. If anyone find tutorials shows how to create/construct real tree, instead of using the speed-tree, it would be great!! Or if you can just tell me how to detect the end of wires or tips of branches, it would be very helpful, too. I think I have to use VEX like a primvertexcount in order to find points that share only one vertex, which should be tips or beginning of root.

To AtomicPerception Thanks for your reply. I took a look at your file, too. So far, important parameters to keep not-bending are: resample node > max segments 1 or 2 (more than 3 are bending a lot) GroupExpression node > @P.y<0.25 0r 0.5 (How many particles to pins also effects a lot. In other words, Pinning only a root particle is not enough) vellumconstraints(hair) > stiffness 1e+10 and dampingRatio=0.1 is pretty good. (1.0 makes bend a lot. 0.01 makes to keep moving/shaking.) VellumSolver node > set constraintIte and substeps larger numbers make less bending After that, I added subdivide node, instead of resample. Then wire gets smooth&curvy.

To Vusta Thanks for you reply. Yeah, I tried your hip file. Motion is very unstable and animation never stop. I think we need something new ideas to make a wire simulation. Otherwise I need to cheat to set gravity zero. Of course, the stretch prevention is so much better than a traditional wire sim. I was thinking vellum could replace the wire sim but maybe not...

hi, I try to use vellum in order to create TreeFX. Then I took two tests with Lsystem, and vellumsolver with wind and standard gravity: 1 - apply polywire and vellumCloth. 2 - apply just vellumHair I set bend stiffness a very large number for the both tests, but branch still bend so much, cannot make stiff well. Setting more substep helps not to bend, but not enough. Does anyone succeed to control bend parameter very well? vellum_v0002.hipnc

hi, I am looking for a way to change a node name automatically by parameter change. For instance, there is a fetch node. When connecting file cache node into source parameter, I want to change fetch's name to the file node's name. To do it, at first, I am trying to use python events. However, any events don't trigger setName code. Thus, I'd like to know how to use these python events, and know how to change node name by parameter change/update. Thanks!

hi, I am a python script beginner and have a quick qustion. I have a null node in rop which connects fetch nodes. The fetch nodes have linked fileCache pathes toward SOP. I'd like to know how to write python script, in order to change a float value in those cache nodes' UI value. I attached a captured picture and example hip file. If anyone knows how to write it, I would it. TST_000_000_fx_tsunami.v001.99.hip

Hi, I have 4 pipeline questions for deadline. If anyone can answer these technical issues, I really appreciate it, thanks! 1. auto ifd delete Can we delete ifd file automatically after deadline finishes mantra rendering? I guess we don't have this feature as default, and need to create and send a external script file to deadline?? 2. save hip file and "submit to deadline" When hitting the button"submit To deadline", can we create a pop-up message like a "save hip file before submit" if a hip file is not saved after modifying it? As default, because there is no such function, I sometimes forget to save a file before sending to deadline renderFarm. 3. auto cache path change by submission When submitting, I want to change cache path by script. When doing local sim, pre-render script takes care my python script to change cache. As the same way, I wonder how to execute or change cache path by deadline submission. 4. frame dependency for sim When making ifd and mantra jobs, I think deadline sets a frame dependency to mantra job. Then, I try to make a same system for flip sim and particleFluidSurface generation. For example, a flip sim has 100 frames. Normally deadline needs to wait for completion of that job and finally resume a particleFluidSurface job. However, I want to make frame dependency for particleFluidSurface job. Then, particleFluidSurface job can starts immediately from any frames after each frame of flip sim is done, instead of waiting for the end frame of flip sim. So far, I tried frame dependency in deadline, but it seems not working at all. How can we set up frame dependency for these sim situation? Also, can we add this frame dependency with deadline node in houdini ?

Hi, I have a question about how oceanEvaluatenode in SOP, and ocean_samplelayers node in VOP/MAT pick and match up each spectrum and mask. For instance, I start from shell, ocean flat tank. And go to obj>flattank_fluid_extended. There are node network to create a bake_spectra and bake_masks cache file. They split , cache and merged them, and feed to oceanValuate. From there, I delete hifrequency_mask node and created 1 more oceanSpectrums and 1 more custom mask. After that, I don't know how to make a coupling/group of default spectrum & default mask, and sceond spectrum & customMask, before merging all spectrums and masks to output. There are primitive names, phase, frequency, amplitude, pointmask, mask in geometry spreadsheet. I guess they check primitive number or some group attribute to make each displacement group?? Also, what pointmask does do? Thanks!!

Hi, I try to make my default set up. Then I want to make a auto-enable setting for staticObject node, instead of creating/deleting the node every time. This is because whitewater solver, for instance, makes a strange collision artifact if staticObject node does not get any collision objects from SOP. So far, I tried a enableSolver, switch node with if(nprims(surface)>0, 0, 1), etc. None of them works well. Alternatively I made to insert a dummy object in SOP, then the staticObject takes it to avoid artifact. We could unlock the staticObject node and implement nodes in there, but I want to avoid this way because it causes a file size larger. Does anyone have smart ideas to do auto-enable/bypass staticObject node?

Hi, The picture shows an object , create > test geo > add velocity > vdbFromPolygon with vel field > visualize velocity. I wonder how to split velocity to tangent velocity and normal velocity. I guess we don't have a node to do it by one click, and need to work on volume vop/wrangle. If anyone knows how to do it, I will appreciate it, thanks!

Thank you, Bunker, for your tips. 1 - It sounds that we don't have so much chance to use pump and sink node operations. 3 - I will use droplet feature to just detect it, and use wrangle to control droplet externally. And, I am still wondering theoretical aspect like a my #1 question. Houdini'd FLIP is designed to modify the both of particles and field together, or just modify one of them.