I'm completely new to Houdini and I've been looking through some tutorials trying to make some RBD Particles in order to fill a container. I noticed that a lot of people skip using the UI provided and so far seems simpler but I understand things can get complicated.

So I added a Circle and clicked “Source Particle Emitter” then added a Cube and clicked on “Instance Geometry on Particles” which works fine but now stuck trying to make the instance geometry to RBD ?

you need to use Bullet Solver to get rbd collisions, you can still emit your packed RBDs using POP Source in All Geometry mode

however sine H18 you can use RBD Bullet Solver SOP instead, it has Solver/Bullet Object/Emit RBDs option

I really don't understand this at all. Is there any way you could example ? Really wanting to do this just by the UI not manually.

I noticed if I use a Ground Plane for collision it already works with Particles but why not RBD or Static ?

There is an example file with the Emit RBDs feature in the Houdini Help when you search for the RBD Bullet Solver geometry node.

Thanks tried but can't see which one.

This one:


But in general I'm afraid there is no Shelf Button Solution for what you want to do. The RBD Bullet Solver SOP might be the fastest way to get there without diving into DOPs. Either way you'd have to get your hands dirty one way or another

here's a basic setup,

- the emit RBD is in rbdbulletsolver>Bullet Object tab
- check in rbdconfig for how I configure the balls, funnel and bowl
- I used quick and dirty concave for collision, beware the pros will frown on this.

and one with animated funnel…

That's a big help thank you. … Should note the Ground isn't working properly so everything falls.

espr3ss0
That's a big help thank you. … Should note the Ground isn't working properly so everything falls.

Ground works perfectly for me.

There is an error on load … Warning: “/obj/geo1/axis_align1” using incomplete asset definition (full definition not found). The following node types are using incomplete asset definition: labs:op/axis_align

When I go into geo1 there is a ground plane visible but can't select it or see any object in the graph.

blackpixel
But in general I'm afraid there is no Shelf Button Solution for what you want to do. The RBD Bullet Solver SOP might be the fastest way to get there without diving into DOPs. Either way you'd have to get your hands dirty one way or another

Thanks I found the file.

I put together a simplified version of the example file, had emitting boxes with a box underneath for them to collide with which seems to work fine but found a similar problem to vusta's file where everything falls down. So I tried taking the example file apart and found that if I replace the RBD Bullet Solver then I get the problem. I'm missing something in the solver but can't see any difference ?

espr3ss0
There is an error on load … Warning: “/obj/geo1/axis_align1” using incomplete asset definition (full definition not found). The following node types are using incomplete asset definition: labs:op/axis_align

When I go into geo1 there is a ground plane visible but can't select it or see any object in the graph.

have you updated the sidefx labs tools ? to be safe just do it

if that's not working…then stuff would be initially below the ground hence fall…even tho the ground is there.

The labs align SOP simply takes an object, aligns its bottom to be on top of the ground (can do other axis too but 99.99% of the time I align it to be on top of ground)

https://www.sidefx.com/tutorials/sidefx-labs-installation/ [www.sidefx.com]

vusta
have you updated the sidefx labs tools ? to be safe just do it

if that's not working…then stuff would be initially below the ground hence fall…even tho the ground is there.

The labs align SOP simply takes an object, aligns its bottom to be on top of the ground (can do other axis too but 99.99% of the time I align it to be on top of ground)

Thank you soo much ! Just updated and works ok now. I see the Ground Plane is an option in the Solver. One more question on this subject … is there any way to make the object I want to fill static ? Moves around too much.

espr3ss0

vusta
have you updated the sidefx labs tools ? to be safe just do it

if that's not working…then stuff would be initially below the ground hence fall…even tho the ground is there.

The labs align SOP simply takes an object, aligns its bottom to be on top of the ground (can do other axis too but 99.99% of the time I align it to be on top of ground)

Thank you soo much ! Just updated and works ok now. I see the Ground Plane is an option in the Solver. One more question on this subject … is there any way to make the object I want to fill static ? Moves around too much.

piece of cake, so assuming you're using the 1st file I sent, look in tab2 of rbdconfigure, you'll see @name=piece1 is being pinned, ie it's perfectly still, static. All you have to do is use the dropdown list in group and add piece0 to the list (piece0 is bowl, piece1 is funnel)

Sorry thanks, I missed that completely !

vusta
piece of cake, so assuming you're using the 1st file I sent, look in tab2 of rbdconfigure, you'll see @name=piece1 is being pinned, ie it's perfectly still, static. All you have to do is use the dropdown list in group and add piece0 to the list (piece0 is bowl, piece1 is funnel)

I have a sligt problem … I have to add a second attribute where 1 is active and the object I want pinned is 2, if I don't do this the emitted objects also get pinned.

Is this just something I'm doing wrong or a bug ? (Apprentice 18.0.348)