Hello professionals,

I'm a newbie to Houdini FX and recently I'm trying to do a boat simulation but there is a problem I'm face and going through the nets doesn't help me much so I'm asking for help here instead.

I made custom VDB so I can use it for the deforming object shelf tool on my boat and changing the proxy volume, as I checked on the blue guide lines for the collision on the static solver itself and it shows customized VDB completely. After that confirming my own customized VDB seems to work and I head over to the guidedoceanlayer to check on the actual collision to final confirm my collision but the problem here is..

Half of the customized VDB is there but the rest are extruded up til the end of the bounding box of my wavetank simulation size. I had never extruded from my own customized VDB and it looks really fine in the static solver guide lines.

How do I fix this? I had been through some tutorials all I kept having the same problem. Is it my boat making this problem? Thanks for answering and guidance.

/Conan

When viewing the collision layer guide you only see where the collision is currently occurring. If the FLIP does not touch the other parts of your boat then there is no collision so it is not represented in the viewport.

There is no fix needed, this is normal operation. You can confirm this by submerging your boat into the tank. You should see your entire collision surface.

Enivob
When viewing the collision layer guide you only see where the collision is currently occurring. If the FLIP does not touch the other parts of your boat then there is no collision so it is not represented in the viewport.

There is no fix needed, this is normal operation. You can confirm this by submerging your boat into the tank. You should see your entire collision surface.

Hello thanks for the reply, submerge should do the trick but the funny thing is, it does not.
first frame collision shows nothing, 2nd frame as shown on the picture. the collision extruded all the way up to the
end of the height of the wavetank. On the 3rd frame, it goes down but the top part of the boat collision seems to be cut off for the rest of the simulation.

I tried increase length of wavetank and many tricks but to no success. How do you fix this?

That looks like normal operation to me.
The second frame is obviously a glitch but it does not impact the collision working correctly. The hull that is in contact with the fluid appears to be accurate.

You may have a lot of problems with those open railings. Basically take your original boat mesh and use a Clip SOP to remove the top half of the boat. If you expect waves to come over the deck then you may want to build a proxy version of the upper part of your mesh with just crude boxes to block those areas out.

Enivob
That looks like normal operation to me.
The second frame is obviously a glitch but it does not impact the collision working correctly. The hull that is in contact with the fluid appears to be accurate.

You may have a lot of problems with those open railings. Basically take your original boat mesh and use a Clip SOP to remove the top half of the boat. If you expect waves to come over the deck then you may want to build a proxy version of the upper part of your mesh with just crude boxes to block those areas out.

Tried that before, improved a little, but still top part of the boat collision got cut off. Will try that method again next week. Thanks for the answers.

I used another boat, the topo is looking very fine. But the collision insist of cutting it off top part of the boat.
You can clearly see that it got chopped off. How do I not let that happen? I searched everywhere on the net for solutions but to no success again.

Check the boat model for any leaks,(unshared edges)

Or, Convert the boat into a volume first and Convert the volume into VDB.