Slicing a model

[Nellie]

I'm having a problem Slicing a model and was hpoing for some advise,

 

I'm trying to slice a 3D model (Building) using the roof which is curved but CAD just wont do it or even give any error for it, I'v tried changing the UCS, Aligning to it using Origin, exploding the roof and slicing by surface but still I'm having no luck.

 

Has anyone else has this problem before? I'm using Auto CAD2008.

 

Thanks in advance.

[Patrick Hughes]

Try subtracting the roof (if it is a solid) or create a solid based on the profile constructed from the roof geometry and make the sibtraction.

 

Obviously if you subtract the roof you'll lose it in the model so do it with a copy.

[Nellie]

Thanks for the quick reply.

 

I've tried that but still have no luck and its a been put into a new drawing just incase the old one had errors but still nothing.

 

I like CAD but sometimes.......................

 

Thanks

[Patrick Hughes]

Sorry for this basic question but Is the building a solid (not an insert)?

[Nellie]

I have uploaded part of the drawing.

 

As you can see there are 2 solid objects, The roof is in grey.

 

What I'm having probs with is slice or subtracting the (brown) building solid with the grey (roof) solid.

 

Thanks

Problem-1.dwg

[Patrick Hughes]

You will want to extend the roof to envelope the whole of the building part.

 

It is getting subtracted out of the building but because the building extends so much higher the part above the roof line remains intact.

[Patrick Hughes]

Oh, also it appears as though in the front view the roof line does not extend beyond the side of the building so when you subtract it does not completely "slice" through.

[Nellie]

Thanks for the advise.

 

The only reason the building goes so high was just for show, on the original the building is extruded to highest point on the roof but still wont slice, I'll try making the roof overhang more just to make sure and let you know if I have any probs.

 

Thanks again.

[Patrick Hughes]

Yep, I understand why the building was so much higher. Here's what I did to the drawing.

 

I applied a small scale factor to the roof to get it extending beyond the walls. I figure you are just trying for a presentaion and actual scale is not a factor.

 

Then I began a series of slices starting from the highest elevation and working downwards, realigning my UCS as I went, I only needed to do this once or twice.

 

I'm working with r14 which is why I did this. I believe the newer versions allow you to separate two non intersecting solids after a slice which would be much simplified.

 

I meant to say after a "subtract:

Solved.dwg

[Nellie]

All sorted now, your right the roof needed to be extended a little.

 

Its always the simple things that stump me.

 

Thanks very much for your help.

 

Nellie

[Patrick Hughes]

You're welcome.

 

Can I ask how did you construct the roof? I didn't look at it in detail but I'm curious because it appeared to have a contour that I don't know if I'm able to construct in r14. I mostly use simple elements and don't need much in the way of contours.

[Nellie]

I use 2008 so was quite easy, All I did was put myself in the correct UCS draw the shape i wanted as a poly and then extrude via a path.

 

If your software is letting you down I'm happy to knock a few up for you if needed.