I"m coming from Modo and Lightwave…..managed to shatter a cube on first attempt following a simple tutorial, but can't seem to repeat this when using Type. Reduced this to the simplest form by using just one letter which I imported after slicing up a bit from Modo in wavefront obj.

Still can't get it to work, have attached the file here. Maybe someone could please tell me what I am doing wrong, surly it must be very simple. Or will this not work with irregular geometry -some limitation?

Without looking at your file, I think the problem is probably that the geometry aren't fused. The shattering likes to use closed geometry. Try to fuse your geometry and it should make the result better.

graham
Without looking at your file, I think the problem is probably that the geometry aren't fused. The shattering likes to use closed geometry. Try to fuse your geometry and it should make the result better.

Thanks for the reply!

But I am still stuck. Imported the H wavefront .obj and then did fuse, then shatter parameters, then the glue and ground plane. This time it dropped and bounces around but no shattering. Have included 4 files in progression.

Well I've read a bit more in these forums and it seems the ‘shatter’ tool is new and problematic and it is better to have pre-shattered geometry and then use RBD Fracture or RBD Glue. What is the difference, which would be better?

Have a screenshot of geometry that I brought in which was shattered in another program. But what has to be done to make this file work with RBD Glue and Fracture, can drop it as a single object with RDB Object but won't shatter apart.

Append an Assemble SOP to the File SOP in the network view. Now you can use the RBD Fractured Object tool on the shelf to add dynamics to it.

edward
Append an Assemble SOP to the File SOP in the network view. Now you can use the RBD Fractured Object tool on the shelf to add dynamics to it.

Thanks very much for your reply edward!

Still can't get to drop and shatter, can only get it to drop in ONE PIECE.

I don't know if I have done this right. Here is the screenshot. Have included the file as well if anyone could please have a look.

Data flows from top to bottom. So you want to wire the File SOP into the Assemble SOP like in the attached image.

Once you've done that, you want to hit the RBD Fractured shelf tool and then with your mouse in the viewport, hit the enter key to accept the selection.

Thanks again edward for writing.

I believe I did exactly as you said plus (and only) added a ground plane after doing the RBD Fracture. It's still not doing anything. Surely it must be something simple unless a bug? Have included the file.

The order of operations matter. In your file, it looks like you ran the RBD Fractured Object shelf tool with the display flag still on the File SOP, not on the Assemble SOP. Notice the blue shaded area on the right of the Assemble SOP in my picture.

It Worked!!!

Thanks so much for the help edward. (I should have noticed that flag)

No prob. FYI, the display flag controls which SOP gets displayed from that particular object. When the RBD Fractured Object tool is invoked, it uses the displayed geometry.

edward
No prob. FYI, the display flag controls which SOP gets displayed from that particular object. When the RBD Fractured Object tool is invoked, it uses the displayed geometry.

Thanks again for all the info and help.

Wondering is edward or anyone around?

I seem to be having trouble with this same thing again, have repeatedly dropped the letters with no trouble at all.

But trying to duplicate this with different geometry is not working. I try to drop this “statue” (top half of a MakeHuman figure) and the object won't break apart but just bounces and rolls as one piece. Just can't see what is different or the reason for this, attached is the files.

Hi,

Had a quick look at the hip file and it would appear that when you imported the geometry it came in with the geometry in a “default” group. This, I think was what was causing the RBD Fracture node not to work, since all the groups created by the Assemble were contained with in the “default” group.

Happily all you need to do to get it working is delete the group that the geometry comes in with, using a group node (the delete group option is under the edit->delete tab on the group node).

Attatched an ammended hip file, largely because it'll probable make more sense than my rubbush explaination

jujoje
Hi,

Had a quick look at the hip file and it would appear that when you imported the geometry it came in with the geometry in a “default” group. This, I think was what was causing the RBD Fracture node not to work, since all the groups created by the Assemble were contained with in the “default” group.

Happily all you need to do to get it working is delete the group that the geometry comes in with, using a group node (the delete group option is under the edit->delete tab on the group node).

Attatched an ammended hip file, largely because it'll probable make more sense than my rubbush explaination

Thanks jujoje very much for the reply and help!

Don't know how you guys work all this stuff out? I've only done some html and tiny bit of css so am clueless.

Just can't get this to work, have posted 2 files, one just before the RBD is applied and one just after. These were starting again from scratch.

The file you amended has problems when I set the file path (?), 2 screenshots before (no geometry) and after reloading the geometry. (warning: no dop object names specified (?))

I probably naively thought that a node setup can be switched around pretty easily. Tried to swap in the statue for the shattered letters in the first file in this thread which was working fine but no luck.

But don't understand why Houdini is deciding to read the shattered statue different than the shattered letters on import? Both went through the same identical pre-houdini process.

RBD Fracture has a Group Mask option to limit which groups are used for creating new pieces. The value in this file is *, which means each group creates its own piece. Unfortunately, the group SOP is creating the group “group1” with all of the primitives in it. Thus, the RBD fracture creates one object that is the entire statue and lots of small pieces. Since these all overlap, they get stuck together from their surface points and you get a slow sim that can't shatter.

If you open Details View while looking at the DOP network you can see the extra “group1” object.

The simplest and most robust solution is to look at the Assemble SOP. You will note it has an Output Prefix which defaults to “piece”. This means the groups it creates are called piece1, piece2, etc. In the RBD Fracture DOP, set the Group Mask to “piece*”. It will then only use those groups for creating the pieces.

The shelf tool for RBD Glue Object should be setting the Group Mask to piece*, but isn't. A bug has been submitted for that deficiency.

- Jeff

jlait
RBD Fracture has a Group Mask option to limit which groups are used for creating new pieces. The value in this file is *, which means each group creates its own piece. Unfortunately, the group SOP is creating the group “group1” with all of the primitives in it. Thus, the RBD fracture creates one object that is the entire statue and lots of small pieces. Since these all overlap, they get stuck together from their surface points and you get a slow sim that can't shatter.

If you open Details View while looking at the DOP network you can see the extra “group1” object.

The simplest and most robust solution is to look at the Assemble SOP. You will note it has an Output Prefix which defaults to “piece”. This means the groups it creates are called piece1, piece2, etc. In the RBD Fracture DOP, set the Group Mask to “piece*”. It will then only use those groups for creating the pieces.

The shelf tool for RBD Glue Object should be setting the Group Mask to piece*, but isn't. A bug has been submitted for that deficiency.

- Jeff

It finely worked!

Thanks Jeff (and others) for all this help and information.

In the end I left the asterisk (*) in the group mask -RBD Fractured Object (node?) but deleted both the “Default” and the “group1” in the group node. Flying pretty much blind so don't know if this makes any sense, but anyway, Thanks Again!

The shelf tools for Fractured and Glue objects actually deal with adding an Assemble sop and properly setting the group mask when you run them and the geometry does not have any groups on them. They aren't properly handling the situation where you have manually put down the Assemble sop before hand, then run the tool. And adequate solution in my opinion is for the tools to detect if the there are any groups and if there are, check for an Assemble sop and if so, use that sop to set the mask properly.

graham
The shelf tools for Fractured and Glue objects actually deal with adding an Assemble sop and properly setting the group mask when you run them and the geometry does not have any groups on them. They aren't properly handling the situation where you have manually put down the Assemble sop before hand, then run the tool. And adequate solution in my opinion is for the tools to detect if the there are any groups and if there are, check for an Assemble sop and if so, use that sop to set the mask properly.

Thanks for writing Graham. Not exactly sure what you are saying and know that I'm using the wrong terminology when calling SOPs nodes, a pity the terms aren't more standardized across programs.

I attach the file as the solution proposed by a mixture of what people suggested here worked really smoothly and managed to easily do a larger object later.

The crux of the problem (imho) was shattering the object which had to be done in another program as was getting very peculiar or no results at all within Houdini, and thus had to import a wavefront obj which probably caused complications.

For shattering the object I used a very simple free plugin for Lightwave called “Crackit”, which though using a lot of memory, seemed to be very efficient.