OffsetSrf rant


I’m getting mad with OffsetSrf,

  • It’s a tool with only a commandline interface yet with a lot of parameters
  • The options differ based on the input (surface or polysurface)
  • The behaviour differs depending on the input (surface or polysurface)
  • There is no loose option for polysurfaces that would offset loose into a solid perfectly
  • There is no way to offset a polysurface both sides into a solid
  • The options in the commandline dance about whenever I change something.

PLEASE revise this for V6 it’s not that this is a trivial command.

It should have a dialog period

It should clearly distinguish between srf and polysrf, or behave equally

Polysrf should be able to be offset loose into a solid ( make this advanced mode if you will) but planar surfaces with a tangent fillet should be possible to offset loose.

Make it clear what is happening and un-tangle the option spaghetti, for the current implementation is a clear example where a tool was improved under the hood, yet miserably failed to get implemented in a proper way.

@bobmcneel could you read along please:

See the example below when offsetting a polysrf:

choose solid: “hey would you like to delete the input?”
choose non solid : " Hey in that case I can do it both ways, would you like to"

There is no logic behind this whatsoever. How on earth did this get into a release? I’m used to it because as a WIP user we tested the improvements on the workings of offsetting polysurfaces and the UI slowly crept in until it did not bother me enough anymore but
why… is this … this …

PLEASE make sure this type of implementations are prevented, what should a trainer tell students explaining this? How can one take a surface modeler serious that implements offsetting surfaces in such half harted sloppy way?



Thanks for the feedback. I’ll take a look through OffsetSrf and file some issues. These are the ones I’m seeing here…

  • Polysrf’s should have a loose option
  • Polysrf’s as a solid should have a both sides option

Is there anything else concrete I’m missing?

Yes. The dialog.

Hi Brian,


Yes the UI for OffsetSrf ( if that falls in the concrete category)
There are too much options and the option set changes based on set options, making it hard to keep track of the commandline settings: Specifically setting the option loose=yes, discards the tolerance option, this switches the set of options to one less item.
For me it’s hard to keep track of all the options when set in one continuous line of words.
Dialogs like those below are far easier to set and check in an instance.


Thanks, I understand now. You want a dialog box instead of command line options for OffsetSrf. Sorry for being dim… I got confused by the ranting.

Yes, a dialog and comprehensive options.

I’m sorry to confuse you.
It was my confusion about OffsetSrf and the convoluted way to operate it that caused the rant on my end. :wink:


If we’re going to be granted a dialogue box, can it have a Preview button as well please?

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Hopefully not. It should have a live preview…


Yes please! In that case, add up/down arrows for adjusting the offset/section thickness and make it work with the mouse scroll wheel. And highlight intersections with neighbouring objects as you do it.

Give us an inch, and we’ll take a mile :smile:

Here are some reports I filed for future reference. Thanks!

I don’t know if a Polysrf can have the Loose option- my guess is this is not an oversight but a limitation - no way to keep edges stuck together without refitting.


Hi Pascal,

Indeed this might not at all be possible, only in very specific cases…hmmm

I was thinking the same thing but figured I’d let chuck be the verdict on that one.

Looks like OffsetSrf can’t have a loose option for polysrf’s. Here’s Chucks comment from the report…
“This is impossible in general. There is no reason to believe that loosely offset adjacent surfaces will end up anywhere near each other. It might make sense in a few cases, but not if any surfaces are near to being tangent.”

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