I have a cookie cutter operation taking in two inputs - both tubes, to try and create the tip of a pencil. Originally tried using a primitive to get a nice curved tip joining onto the 6 sided pencil. But this produced a a cone that was wider at the base than what it joined onto. So I tried switching it to a polygon.

At which point it promptly crashed, citing a Segmentation fault.
I sent the file to a friend who was able to change it to a polygon and sent it back. Just trying to open that file causes a crash.

Any ideas what's up? I'm using ver. 474.

Cheers,

Alistair

Attached is a recreation of the file - setting tip_mold's type to polygon causes the crash on my system.

Running a Win XP SP2 system, running on a AMD XP2800+ 1GB RAM and an ATI Radeon 9800.

I can't reproduce the crash with H8.0.545.

The Cookie SOP only works on polygons. You saw the issue in that the tube was a primitive and NOT a polygon surface.


In the future, when you want to open a file without cooking any operators and thus avoid a potential crash, you can launch houdini in a few different ways.

If you are familiar with launching Houdini from the command line, you can open houdini with a particular desktop by issuing the command:
houdini -s textport myfile.hip
Then you can do a couple things:
-use hscript to turn off the display of any objects or move the offending SOP display flag further up the chain.
-Change the desktop to a network pane and change flags graphically. Don't use the MMB on any icons as thihs will force the nodes to cook.
Both ways will launch houdini without cooking any geometry.

Another way is to just launch Houdini and just change the existing desktop to view a single network pane and save/quit Houdini. Next launch your file and the desktop changes will be remembered and once again not cook your scene.

Does this mean it's likely to be my hardware?
I might be able to borrow my friend's graphics card and see if that changes things.

Would the recommend course of action in the meantime be just to remove the offending cookie operation and avoid using it?

Cheers,

Alistair

It's most likely the houdini build more than anything else. What build are you using?
If it is a graphcis error, then Houdini will just blow away without warning.

I have attached your file modified by me. It works just fine now.

Some comments:
-Don't be shy with the divisions. I added twice as many divisions to the polygon tube. I was ready to add a subdivide SOP to the pencil shaft with a high creaseweight just to divide the poly faces flat but the cookie was doing fine with just the added tube divs.
-Didn't need the end caps in this particular case. Yes geometry should be manifold but if the primitive normals are facing outward for both inputs and the shapes are farely convex, then go with open geometry
-Don't make things precisely exact. I moved the pencil down slightly and voila, no problems with cookie on the tip. The adage just because you can doesn't make it right. Just get it to work and move on.

To answer your question, if you are stuck with a crash on load, launch houdini in such a way as to not cause cooking and then yes, remove the offending SOPs and try again.

One of the basic steps we take here in support to build work-arounds. 8)

Was originally using the build before 474, and switched to 474 to see if that fixed it, but it didn't.

Main reason I only used 6 divisions for the pencil tube was I was going for a hexagonal pencil shape. As for all th subdivide SOP, I'll look that up in houdini when I get home - I'm pretty much completely new to houdini

End caps - noted for future use.

Precisely exact - do you mean it removed the overlap I orginally had using a primitive?


I'll have a look at the houdini file when I get home and have a play. Thanks for the time and effort to help

alistairg
Was originally using the build before 474, and switched to 474 to see if that fixed it, but it didn't.

Upgrade to the latest latest and try that build.

alistairg
Main reason I only used 6 divisions for the pencil tube was I was going for a hexagonal pencil shape. As for all th subdivide SOP, I'll look that up in houdini when I get home - I'm pretty much completely new to houdini

To just add divisions to a polygon face and you want to keep the original shape exactly intact, there are a two techniques that I emply in the order of how frequently I use them:
-Use a Subdivide SOP on those faces I want to res up. By matching the subdivision depth value with the crease weight value, you are ensured that all edges will remain at the same angle (no smoothing will occur) and you just end up with nice quad divisions. If you want to turn your model that has a mix of ngons (triangles, quads, penagons, n-gons), just run it through a SubDivide SOP and you are assured to get only quads. Adjust crease weight to your liking.
-Use the Divide SOP and just use the bricker option. This one is tricky for two reasons: It cuts up the geometry in local X, Y and Z space. It is input geometry size dependent and can use up all the memory on your machine if you use too small a value. For these reasons, I rarely use the Divide SOP to dice up polygon geometry any more.

alistairg
Precisely exact - do you mean it removed the overlap I orginally had using a primitive?

Yes and no. First omitting the endcaps on the tube fixed the overlap problem at the top of the tube. The moving of the pencil shaft down 0.02 units down got rid of the radiating polygons at the point of the tube. The tip of the tube was intersecting exactly with the base endcap of the pencil shaft.

Phew, Houdini is like playing chess. The better you get, the more often you win. It takes lots of practice.


Some say I use analogies too much…

jeff
I can't reproduce the crash with H8.0.545.
In the future, when you want to open a file without cooking any operators and thus avoid a potential crash, you can launch houdini in a few different ways.

If you are familiar with launching Houdini from the command line, you can open houdini with a particular desktop by issuing the command:
houdini -s textport myfile.hip
Then you can do a couple things:
-use hscript to turn off the display of any objects or move the offending SOP display flag further up the chain.
-Change the desktop to a network pane and change flags graphically. Don't use the MMB on any icons as thihs will force the nodes to cook.
Both ways will launch houdini without cooking any geometry.

This I didn't know. I thought I was doomed to cook offending operators
Very good tip.

Thanks!

/Rick

jeff
Phew, Houdini is like playing chess. The better you get, the more often you win. It takes lots of practice.

I just Hope I get that much practice

Just had a look at the file - lots of stuff for me to play with and learn how to use there - never used a blast fuse or blend before so I need to spend some time and learn what they do. I think I can work out what fuse does, blast I can see what it does (although I need to go and learn how to select what it operates on etc) but blend I don't have a clue what it does, so I'll need to have a play.

Lots for me to go away and learn

Also after playing around with the example it's only if I bypass both fuse1 and xform1 that it seg faults. Either one of those and it doesn't happen.

Found another set of graphics drivers (omega) and will try that and the daily build and see if that stops it seg faulting.

Cheers

Another very useful option is

houdini -n your.hip

The above starts Houdini in “Never” mode so you can delete or change the flag of an offending OPerator.

Cheers!
steven

We're on 2023 and the error still exists. What a shame SideFx

Pavini
We're on 2023 and the error still exists. What a shame SideFx

relax I've experienced that crash in all DCC and tools that somewhat are taxing on the GPU for the past 15 years.
Houdini, for the most time, crashing gracefully with a tempfile saved and a proper Failure message.