hollow objects in ODE

[MENOZ]

hi, I have a static cylinder and I want to fill it with other objects using ODE solver, but I can't find how to create the hollow object (the cylinder).

I tried to use the Composite object, but ode solver seems to ignore it. If I use sphere, cube or something else it's ok but i haven't the hole.

is there a way to do this?

thank you

EDIT: composite object, even if it's a simple box, are ignored from the collision. only works with the build int primitives. it's a bug or am I missing something?

I remember an example in the help with an airplane composed of many shapes, but i can't fint that page anymore.

Edited November 8, 2010 by MENOZ

[Emanuele Berti]

Hi Andrea,

if you are using a simple box it should work fine...

did you set that object as active too?

Anyway, I believe the ODE wants some primitive geometry as input (box, sphere, ...)

So, as you can see in my scene inside the cyl geometry node: I put two ways, one that subdivides the cylinder in boxes giving the collisions we would expect and the other one that just uses a cylinder as it is without success.

Is this what you are after ?

Emanuele

ODE_example.hipnc

[MENOZ]

Hi Andrea,

if you are using a simple box it should work fine...

did you set that object as active too?

Anyway, I believe the ODE wants some primitive geometry as input (box, sphere, ...)

So, as you can see in my scene inside the cyl geometry node: I put two ways, one that subdivides the cylinder in boxes giving the collisions we would expect and the other one that just uses a cylinder as it is without success.

Is this what you are after ?

Emanuele

Thanks, are you italian?

ok it works, but i don't understand what is the geometry that is accepted by the ODE solver. how does it know that it's a sphere or a cube? and what are the primitives that are accepted? thank you!

[Emanuele Berti]

Yes I'm from Milan.

To answer to your question... even if I'm not an expert...

ODE solver accepts every geometry you pass to it... the way it represents the geometry can cause problems:

so, to be a bit more specific it likes primitive shapes like box, sphere,... or composite (a mix of them).

That's why I created boxes from the original cylinder's faces.

Cheers,

Emanuele

[MENOZ]

Yes I'm from Milan.

To answer to your question... even if I'm not an expert...

ODE solver accepts every geometry you pass to it... the way it represents the geometry can cause problems:

so, to be a bit more specific it likes primitive shapes like box, sphere,... or composite (a mix of them).

That's why I created boxes from the original cylinder's faces.

Cheers,

Emanuele

yeah, digging into the ode configure object mayabe could clarify more how it process the geometry and what are the primitives that are supported. It was just a curiosity, for now I will use the ode solver as is

thank you