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DrStrik9
11-04-2015, 06:39 PM
LW 2015.3:

I'm trying to use Fracture to break up some objects. The issue I'm having is that using the default set-up (nothing in the background), I'm getting some wild offshoots of points -- making spikey polygons that don't fit within the original object, and even some stray points, also outside the volume of the original object.

I can just selectively delete the extra points, but I'm not sure how to deal with the crazy-spikey polygons.

(I'm in Modeler, not Layout.) -- What is the best way to deal with this problem?

Thanks for any advice.

prometheus
11-04-2015, 06:49 PM
Rob Powers are giving some tips regarding fracture and incorrect stray points and what type of geometry best suited for fracture, they should often be divided first for a cleaner geometry, even so..have the numerics panel open and you can select stray points easier from that...

Check around 1:30 in the clip where he covers that..the rest is about chronosculpt, which you donīt need for this of course.


https://www.youtube.com/watch?v=yqexUbvLTxg

DrStrik9
11-04-2015, 07:05 PM
Yes, I keep the stats panel open always, and can easily delete stray points. That's not the problem.

The problem is all the wonky/spikey polygons that don't fit within the original object.

I'm attempting to fracture formerly sub-D objects which have been frozen using a sub-patch division of 2. I'm attaching an example of the problem.

130770
130771

I've tried just randomly dragging those spikey points inside the object's volume, but this leaves some pretty big holes in the fractured parts.

prometheus
11-04-2015, 07:12 PM
depends on what fracture method maybe?
but we donīt know what you used.

best would be if you post the object, along with exact fracture settings you used, testing my own subpatched freezed object works fine, but that tells nothing since it isnīt the same model etc.

DrStrik9
11-04-2015, 07:20 PM
I could post the model, no problem. But I've had this same issue with all other models I've tried fracturing before as well.

Here is the Fracture set-up. Just try it on any reasonably-detailed model, which is air-tight and clean ...

130772



... I'm just hoping there is some kind of workaround that others have used to overcome these errors in Fracture.

ernpchan
11-04-2015, 07:32 PM
Fracture is a finicky tool at best. Scale is important. Try not to be too small or too large in size. I've also heard that having your geo sliced up with polygons that are of equal size helps.

I think some people do fracturing in Blender too. You could also try the 3rd Powers tools.

DrStrik9
11-04-2015, 07:41 PM
In fact, it doesn't matter whether I use the same default setup with Veronoi, or Matrix, or Halves. I ALWAYS get the extra spikey polygons extending outside the original object.

I understand Fracture is a very special kind of thing. Attempting to fracture an object manually is a nightmare (I know; I've tried it in the past) -- I just need to discover the best way to overcome Fracture's flaws ...

Or could it be a Mac Modeler bug? Does Fracture cause similar errors on PC Modeler?

Thanks for any help.

DrStrik9
11-04-2015, 07:48 PM
ernpchan: I've looked at the 3D Powers stuff: impressive. But I'm not really seeing anything that might do the job of Fracture ... Are you thinking maybe their Boolean Tool?

On model size, it doesn't seem to make any difference. I've tried from 5% to 500% their original size, but I always get the same kind of errors.

prometheus
11-04-2015, 08:19 PM
ernpchan: I've looked at the 3D Powers stuff: impressive. But I'm not really seeing anything that might do the job of Fracture ... Are you thinking maybe their Boolean Tool?

On model size, it doesn't seem to make any difference. I've tried from 5% to 500% their original size, but I always get the same kind of errors.

I do not get that issues with fracture...even though I freezed subpatches...the thing though, it doesnīt matter if you post the settings and an image..it doesnīt help to solve the case with one part only..you need to post the model too.
And another thing...what lightwave version?

ah..noticed mac...you asked about error in pc...no...but that doesnīt help you, since we are working on different models...post the model and your lightwave version..then we can exclude stuff and probably track it to mac :)

prometheus
11-04-2015, 08:23 PM
ah..noticed it was lw 2015.3

used that too..I do not get any issues on pc...but post the model so we can bash macīs

DrStrik9
11-04-2015, 08:50 PM
Here it is. Thanks for trying this. I now suspect it's a Mac Fracture bug ... but we'll see ... :+)

130773

It's LW Modeler 2015.3, but 11.6.3 and earlier versions have this bug too.

prometheus
11-04-2015, 09:00 PM
well..I got those errors too with your model..if that makes you happy..
will take a look an see what it can be..at least it might be a model issue and how that is constructed..not a mac issue..nor something wrong with your system...just the model, but I do not get things like that on my stuff..so far at least.

Think it could be non planar polygons causing it.

tripling helped a bit..but still some spikes.

prometheus
11-04-2015, 09:18 PM
I got a clean fracture now,go to detail polygons/more...and make it double sided..that did it for me.

DrStrik9
11-04-2015, 09:19 PM
Yeah, I tried tripling too, with same errors.

Unfortunately, it's from a sub-D model, which will almost always have non-planar polys.

- - - Updated - - -

WOW! I never even thought of that. THANKS! ... Will try it asap.

prometheus
11-04-2015, 09:26 PM
Yeah, I tried tripling too, with same errors.

Unfortunately, it's from a sub-D model, which will almost always have non-planar polys.

- - - Updated - - -



WOW! I never even thought of that. THANKS! ... Will try it asap.

there is a problem though when fixing it with double sided, when unconnecting the pieces..they will be hollow..and that is not good.
..I am sure there must be away around..but I will leave that for someone else..have to go to bed now.

DrStrik9
11-04-2015, 09:59 PM
I'm still getting the same errors, even though the model is now double-sided.

Oh well ... it was worth a try.

I'm trying just brute-force deleting any offending points and polys. Maybe the interior surfaces with holes in them won't show too much as everything is getting destroyed ...

prometheus
11-04-2015, 10:04 PM
I'm still getting the same errors, even though the model is now double-sided.

Oh well ... it was worth a try.

I'm trying just brute-force deleting any offending points and polys. Maybe the interior surfaces with holes in them won't show too much as everything is getting destroyed ...

I donīt think you followed me correctly..as I said ..go to detail/polygons/double sided....not double sided in the surface editor...which I believe you have done?..and that will still cause issues...if you did follow my route..then it would be weird.

tried all possible ways ..but canīt solve it currently, tested some non planar fixing plugins, but no improvement.

DrStrik9
11-05-2015, 03:45 AM
I donīt think you followed me correctly..as I said ..go to detail/polygons/double sided....not double sided in the surface editor...which I believe you have done?..

Yes, you are right. I'm getting more than a little punchy. :+) I made the polys double-sided as you suggested, and this has greatly improved fracture. Although there are still errors, they are far fewer. But you're right, this isn't the perfect solution.

I used fracture on these double-sided polys, then tried unifying polys. But the errors show up worse than before this way, and after fracture, of course most of the polys don't unify. Merging points does some good, but the model looks pretty weird at this point.

I appreciate your help very much. It's nice to have another mind thinking things through with me. So far, in rendering tests, simply deleting offending polys is the best result so far, although not perfect.

Oh well. Time for bed. Fight again tomorrow. :+)