Marcocheng

Oh i see i just want to try things differently anyway thanks a lot!

Hello folks! I'm trying to do some collision geo decomposition using Voronoi fracture (second cut) to generate a Bullet decomposition mesh but unfortunately, Houdini became no response to the infinity. The ram shows I got plenty of space left and the CPU usage turns down from 50% to 8%. Here are the steps: 1. I use a Voronoi fracture to frac hero pieces (a thousand pieces, some of them are not fit into convex hull shape) 2. I fracture them per piece with another Voronoi to decompose a geometry 3. Single-pass preview is fine for me but then when I do it for all then Houdini froze half way round and to clue what does it cause. Here is the network: (I've try both single For-each loop or Compile-For-each loop combo, both fail at the middle) For-each loop stop (Houdini freeze after processing no.199 piece) and I still got plenty ram and computational power Here's the file to help diagnostic. Thanks a lot! VF Problem_HIP.7z VF Problem_HIP.7z

One possible reason (assume you make everything correct in SOP, grid size and volume injection), try to toggle solve on creation frame (in pyro solver) so the smoke can initialize in the first frame. but again a file is better than nothing

Can you post a simplified hip file so that we can analyse it better?

Source from debris than using those points as emitting pyro. Sure you need to inherit velocity.

Hi I think the model didn't intersect with the ground initially. The model drops at the beginning. The result seems to be better after increasing the rotational stiffness. In geo spreadsheet, i can still see the V and W jittering (very slightly and non-stop)... The look is okay but not good when you see the data

Hello guys I'm just doing simple RBD sim and basic glue constraint network relationship. As usual, connect adjacent pieces. When the RBD packed object drop to the ground the object spin around like crazy. Even do some parameter tweak still you can see velocity is non-zero after the object reach the ground and keep shaking after hundreds of frame Here's the file RBD_Simple_Jitter.hip Can anyone tell me what may cause this issue? THanks!

correct. Since i have pre-roll in my sim, you definitely need to copy your creation frame number into rest field offset.

Thank you Tomas. Prehaps starting frame not equal 1 causing the empty rest field result? PS:emm i found offset the rest field works fine, thanks again!

Hello folks! I'm currently playing with pyro with volume displacement (Arnold), i have to convert my volume into vdb so that it can rendered with Arnold, i plug the convert VDB after my volume cache, rest and rest2 field turns zero. I wonder what causing that. I'm working with Houdini 16.5. Convert VDB sop remains default value and parameter. Before convertVDB: After convertVDB Hope for an anwser! Thanks! Also if there is a way to combine each scaler field into single vector field? thanks again

Hello Mangi, Wow, that's a very detailed test. Thanks for spending time on this first of all. I've actually tested the render with AOV output (diffuse + specular pass), the flickering seems to happen in the diffuse ray as well (while the specular pass is black when I switch off specular attribute in Arnold shader)... I'm not 100% sure the flickering was caused by the specular... And yes I'm a v16 user... I don't know if they upgrade the standard shader in v17 (both are arnold 5 right?) Please to have more info with that! Seems to disable specular and increase light sample might help... regards Marco

Post the file otherwise we hard to follow the problem... btw if not, try to you volume vop to increase the contrast of the smoke sim and run the POP again

Here's the file, just load the animation in it... and cook the rest. Have a nice day. Animation.7z GrainFirstEverTest_v001_Publish.hip

Hi, I crop out some of the particles by using a group node (by a geo) and a delete node to reduce cache size (that's why some of the particles seem to disappear when they reach the bound), the cache cost 16GB of space, let me upload the source setup HIP and you cook all the node. Sorry for the confusion Cheers

I think the camera angle also matter to the flicking issue. You will get less flickering while grain facing the camera. But when the grain is larger facing angle to the camera you will definitely get more flicking. (random dots flicking) To my instinct, it seems like a pixel filtering issue... Flicker.mov First: Grain facing the camera Last: grain isn't directly facing the camera (larger facing angle). Edit: More test today. I render several AOVs out for debugging and increase the directional light sample from 1 to 4. It doesn't help, and the flickering appears in the direct diffuse layer. Flickering_DiffuseDirect_4LightSample.mov