Hi guys. This is my first post on Houdini forum. I have some problems with dynamic object that i want to collide with a fractured object.

I create a fractured object in houidini with voronoi. Then i animate a sphere in Maya, i make cache for geometry and animation and export it as alembic simulation.
After i have imported my alembic in houdini (the animation works fine) I create a RBD fractured obj from my fractured obj and set my animated sphere as static obj.
When i start the simulation my sphere doesn't collide with my fractured obj but run througt it.

I also try with a rbd obj and a terrain obj but it doesn't work. My sphere with animation cached never collides with my RBD fracture OBJ.

Thanks for attention

Giovanni

Did you turn ON “Use Deforming Geometry” option in the static object !?

If No ,Select Static Object for sphere in the AutoDopNetwork and Turn On “Use Deforming Geometry”

Joker386
Did you turn ON “Use Deforming Geometry” option in the static object !?

If No ,Select Static Object for sphere in the AutoDopNetwork and Turn On “Use Deforming Geometry”

Hi, thank you for answer. It still doesn't work. I have the same problem with a sphere created and animated inside Houdini. I don't know why.

what is the the correct pipeline to ensure that an animated object, imported in Houdini with alembic, collides with an RBD fractured obj created in Houdini?
Thanks a lot.

Giovanni

Oh ,I didn't know you used Alembic object !

About Alembic objects you should convert your object to the Houdini Standard type or polygon with two way :

1. Select “Alembic SOP” and set “Load As” option in the Geometry tab to “Load Houdini Geometry”

or

2. Append “Convert SOP” after “Alembic SOP” to convert Alembic type to the polygon

Of course I suggest you to use “Alembic Delayed Geometry” and convert it to the polygon later ,Because in this case you have animation data between each frame (Something like using “Time Blend SOP”) ,So you can change speed of the animation very easily with “Time Wrap SOP” :idea:

In the below pictures I slowed animation for both method ,you can see in the second method ,our animation stopped after certain frames ,But in the first method ,Our Animation's curve is so smoothly 8)

I'm sorry but i couldn't check your answers.. My internet connection didn't work.

So, i've riassembled a new scene with a ground fractured in houdini and imported inside it with an alembic as “houdini geometry”. Then i created a simple cube falling down on my ground.

At this time my cube falls down on the ground and collide wirh it but, when the fractured grouund pieces fall down, the cube doesn't fall.

I think that the cube consider the entire ground bounding box and doesn't consider any single pieces.

I'm sorry for my bad english.

Giovanni

Please ,Upload a simple example if you can . 8)

This is my simulation. The ground is an alembic file, the cube an rbd object.
Thanks a lot.

Giovanni

Check this file ,Is this OK in your Houdini !?

Yes. It works fine!