Extruding shapes

Hello,

I am in the process of drawing this bookshelf:

As already visible on this picture I am having trouble with extruding some of the shapes of the shelves.

The tricky thing is I have little to no idea what I have been doing differently with the one shapes where the extruding leads to the desired result and the others where it does not work. I have been trying different things: changed the shapes from splines to polylines etc. Does not work...

Any ideas?

I´ll add a reduced version of the drawing here: the original shapes are on layer 0, the extrusions on 0 - X

Drawing2.dwg

Thanx in advance!

Take a good close look at the profile for the shelf that is second from the top. Do you see a second profile?

In situations where splines are being used the PRESSPULL command would be a better choice over EXTRUDE.

Are the profiles for each long shelf different?

Addendum:

By my count there are at least two surfaces and five splines. See attach drawing saved in AutoCAD 2010 file format.

ShelfAnalysis.dwg

OK I know nothing of the MAC/PC thing, and I use LT anyway so a lot of 3D is beyond my reach. But looking at your drawing you have quite a selection of types of geometry, I will throw in a guess that the problem is with the geometry not being 'closed'. Pick an object and look in the properties palette some of your geometry is closed and other areas are not. As far as I can see the extrude command needs closed geometry to create a 3D solid wether that is a circle polyline region etc. it needs to be closed.

PM me with your email address and I'll send you a copy of your drawing with the horizontal shelves fixed. It's 1.5MB as a DWG or 860KB as a zip file. Your choice.

What version of AutoCAD are you working in? Duh! It was right there in front of my nose. Gadz! Sorry.

I didn't realise this but when drawing a polyline if you finish the polyline by clicking on the starting point, it isn't actually closed, you do need to finish with the "C" option to get a closed polyline, you can also close the polyline later using the pedit command - or even just picking yes in the properties palette for closed (providing it does not actually have any gaps - or an extra line will be added). This is possibly the cause of your problems, the region command which needs a closed area will accept an open polyline apparently extrude won't (I cannot test this) and so extrudes just a surface instead of a solid.

What is your preferred method of creating the shelf profiles? The only one I would avoid is the 3Dpolyline, otherwise you should be able to PRESSPULL/EXTRUDE all the other profiles, however as others have pointed out, your success will depend on whether the profile is closed.

Having said that, some of the shelves that "should have" extruded, wouldn't immediately. FLATTEN and/or BPOLY seemed to resolve whatever issue(s) were causing them to be troublesome.

Thank you for your responses.

ReMark: Looks like your first guess was right. The problem is that in case of the relevant shapes when extruding (or presspulling) surfaces are being produces and not solids. (PRESSPULL didn´t change anything by the way). I´ll pm you after writing this post. Thanx for the fixing!! But I´d also like to know where´s the bug in that thing!! And, yes, non of the long shapes are equal. Sorry about sending a drawing that´s not really cleaned up: for drawing the shapes I used splines. For being able to join them with the straight lines and extrude them I turned them into plines. The splines remained...

steven-g: the second from the top shape is actually not closed, your guess on that was right. Still it will let itself extrude. (Only with the non desired result of turning into a surface). Instead when I close the pline I am not able any longer to extrude it... But: if I look at one of the shelves where the thing worked, I find the basic shape to be closed....Confusing...

I´ll attach a more reduced drawing here, with only one shape:

Drawing3.dwg

I put your drawing on a diet in order to upload and attach here. The three problematic shelves are now solids.

Lentezza Shelves 3.dwg

steven-g: the second from the top shape is actually not closed, your guess on that was right. Still it will let itself extrude. (Only with the non desired result of turning into a surface). Instead when I close the pline I am not able any longer to extrude it... But: if I look at one of the shelves where the thing worked, I find the basic shape to be closed....Confusing...

I would imagine that is how it works Autocad automatically creates either a surface or a solid, using the extrude command, if it's not closed Autocad sees it as a line and can therfore only create a surface, just select the polyline and change the closed property to yes. then it should extrude as a solid, but as I say I have LT it could be something to do with the UCS plane, the original drawing you posted has the UCS set to front, so I doubt you can extrude 'up' untill the UCS is pointing in the up direction, but again I'm just guessing on that. It is just how the polyline command works, it will only create a closed polyline if you tell it too close the polyline. Or try one of the other options given.

For the 3DPoly shelf profile, Try switching to top view (PLAN) and FLATTEN it. You should then be able to EXTRUDE or PRESSPULL it into a solid

However as I mentioned earlier, if you can use arcs and splines, the solids will be less complex with smoother/less-segmented edges.

That is a 3D polyline maybe extrude doesn't like them either ?

Try just the polyline (closed)

Drawing3.dwg

Have to go to the workshop, will be back tomorrow....

Are all of the curved shelves the same size(looks so in the picture)? If so just create 1 and copy it for the others. No need to keep making the same shape over and over if you don't have to. Good info from Remark, Nestly and Steve-G

I thank you all for your posts. I give up. I started this drawing a view months ago already. I got really angry when this problem started appearing. Then I moved house. Now I got back to the drawing so I finally wanted to find out...

When I was drawing the basic shapes of the shelves I had trouble JOINing the curves (splines) with the straight plines. In the end I made the curves out of plines turned into arcs.

However... I tried applying your advices - nothing seems to work. I could not find out how to change the 3d pline into a simple pline. (How did you do this steven-g?) FLATTEN does not exsist in the Mac version unfortunatly. (Thanx for the animation, Nestly!)

So in the end I decided inserting ReMarks fixed shelves. I still would be curious how you did it, ReMark. But maybe the differences between the Mac and PC versions are too many...Nevertheless I had the occasion again to learn a view more usefull things.

f700es: no, as said already before, the shapes are not equal. I agree with you for the rest.

It has nothing to do with the differences between the Mac and PC versions of the program.

I simply copied and pasted your shelf profiles into a new drawing and used PRESSPULL to give them a height. Then I copied and pasted them back into your drawing. I can't explain why that worked except I came across a similar problem here over the weekend when I was playing around with a drawing of a railroad flat car that someone was having a problem with. He too kept getting surfaces instead of solids. Try as I might I could not consistently overcome the problem in the original drawing. That's when I decided to pull his geometry into a new drawing and it then worked. Maybe nestly can clue us both in as to what was happening.

Glad to hear my shelves were of use to you.

You can use 2 methods to create a polyline from the 3Dpoly. Explode and use the Pedit command to create the polyline or use the Boundary command and pick a point inside the 3Dpoly.

OK I finally had a chance to look at the dwg. Why aren't the curved shelves the same? When looking plan view they look just like random sizes, why not make them all the same? It would make the process a lot easier.

As you can see they just seem random.

Not trying to be critical but as I said one shape would help matters.

In my first post I asked if the shelf profiles were the same but never got a reply. It was only after I delved deeper into the drawing that I realized they were different. I agree that it would make things much easier.

AutoCAD has a lot of idiosyncrasies about what type of object can be used for certain tasks, and also can be finicky about converting objects into other objects. For the most part, I think if you FLATTEN the objects in WCS/Plan view, either REGION/BPOLY would give you profiles you could PRESSPULL/EXTRUDE into solids.

In my first post I asked if the shelf profiles were the same but never got a reply. It was only after I delved deeper into the drawing that I realized they were different. I agree that it would make things much easier.

Well I have had a hand in store fixture design before and having one shape will make it a lot easier (and cheaper) to construct. I think the OP needs to work out their shelf shapes in 2D 1st and once they are OK with the design then take it to 3D.

Again starting with a good 2D closed polyline will make the progress from 2D to 3D a lot easier. This is how I used to do it when I did fixture designs and layout with a certain doughnut company