View Full Version : Boolean Operation Causing Lightwave to Hang
14th February 2008, 02:11 PM
Hello! I was discussing the following problem with Panaristi over in the WIP section and thought maybe I should post my question here for assistance from other Forum members.
I have been trying to create a grid / floorplate with an inlaid diamond pattern like Panaristi has on the fenders of his StuG 33. I also want to make a grill with a similar cut-out pattern to put over an engine vent.
The problem arises when when I go to do a Boolean Subtraction to remove the diamond shapes from the plane / rectangle (I've tried both a single polygon face and a rectangular box shape). When I click Boolean, Subtract the application hangs / locks up on me. I thought maybe it was doing calculations in the background, but the program was still unresponsive after about 30 minutes and I had to kill it via task manager.
Is there some other method I should be using to create the floorplate / screens?
I'm running a quad-core with 4GB of RAM, and running Lightwave 9.3...
Any help / guidance is greatly appreciated!
14th February 2008, 02:23 PM
I always try to distill it down to the simplest component to make sure I haven’t introduced an error. I would try cutting one pattern shape from a single flat ploy square and see if it hangs on that. If it does then take a closer look at your pattern and you’ll probably find a set of double points or perhaps it’s not completely flat. If it does work then my guess would be you are trying to do too much at one time. In that case try to do half of your plate and the mirror it or clone it.
14th February 2008, 02:51 PM
Thanks for the quick response, Bob! I was able to make a very small section using the method you mentioned, so I'm guessing it's a matter of throwing too much at the application / processors at one time. I'm just not sure how to do a small section and seamlessly "tile" it into a larger plate / grill...
I'm quite new to Lightwave (and 3D modeling in general) and have soooooo much to learn! :confused:
On a related note: if I want the diamond pattern to have rounded points, would you round off the diamonds before you cut them out of the plane, or would you do the boolean with just the bare-basic shape then bevel / round the end product (mesh plate / grill)? I had rounded off the diamonds first, and I'm wondering if that may have contributed to "overloading" poor Lightwave's brain! :p
14th February 2008, 03:16 PM
First, the rounded points. I would do that to the pattern first. I just think you will find that easier.
Next, on cutting smaller pieces. If you can adjust your pattern to fit neatly within a square you could subdivide the large square into smaller ones of the same size. Then you could boolean sets of the smaller squares until the entire surface is done. That might be the easiest without having to line up the polys and stitch them back together.
However, if you machine will handle it you could do a row of the smaller squares and then use the clone tool to extend the row several times. You just need to know the size of your squares to offset properly and everything should line up, at least in theory.
Hope that made sense.
14th February 2008, 03:22 PM
It did... I'll give it another whirl tonight... :)
14th February 2008, 04:14 PM
When I need to do something like this, I always set up all of my patterns in a layer. Then I will copy, oh maybe 10 or 12 to another layer, then Boolean those. Then copy another 10 or 12 to a new layer, and Boolean those, repeating until I am done. My machine cannot handle doing large Boolean operations either.
Also, the Boolean operations tend to go a lot faster if the piece being cut has more polygons; triple the item first then reduce polygons afterwards if need be.
14th February 2008, 07:02 PM
If its the type I think then then I wouldn't bother with booleans at all. If you mean like a diamond shaped grill work then try this way.
Make a flat plane. I made mine 1m x 1m and gave it 25 segments in the x and z
Rotate it 45 degrees and then use the stretch tool to stretch it in the Z axis about 200%. If you hold down ctrl or use the MMB it will constrain it to one axis.
Now I don't know if your looking for a serrated edge or a smooth one so I'll do both. Smooth on the left and serrated on the right.
Select the middle and first row up. Cut them out. Press delete to kill the rest and press paste. You'll be left with this.
http://www.foundation3d.com/uploads/instruction/2008/02/8-14-35341_tn.jpg (http://www.foundation3d.com/uploads/instruction/2008/02/8-14-35341.jpg) http://www.foundation3d.com/uploads/instruction/2008/02/8-14-35364_tn.jpg (http://www.foundation3d.com/uploads/instruction/2008/02/8-14-35364.jpg)
For the smooth side... delete this point.
Copy this row and paste it in a new layer. Now with the original in the background, zoom in and move it up the Z axis until the points match up. When its in place, hold the mouse button and look in the bottom left corner. It will tell you how far you moved it. Mine was 113mm.
Your done with this layer.. you can delete it now. We just needed that number. So back to layer #1. Goto the multiply tab and select Clone. In the requester that pops up type in the value you got (113mm for me) in the spot for Z offset and set the # of clones that you want. I put 25.
Press OK and you get this.
Now merge points (press m) if it doesn't report any merged then do it again and instead of automatic change it to fixed and set it for a couple mm, depending on your scale.
Now for a smooth side you need to fill the top and bottom edges. Select 3 points and press p. Repeat until the bottom is filled with triangles.
Select everything and zoom in close to a corner. Press b for Bevel. Again hold ctrl or use the MMB and inset them some. I did it 2.5mm. This # will be doubled since its beveling both sides at once. When your done hit spacebar to drop it.. It should look like this.
Now since the polys that are filling the holes are selected... just hit delete.
If a 2D plane won't do it .. a simple extrude will give it some depth and make it solid.
And no booleans :)
14th February 2008, 08:56 PM
BillS grate minds think alike!!!!
I did somethink like that for my panels on my HMS Tabard, did all the cutting in 2D then muti-shifted to sute the 3D look.
15th February 2008, 04:41 AM
If I read you correctly, You are trying to create a punched mesh grill like that on a car etc.
If so, Under no circumstances should you ever have to use sloppy shortcuts like booleans as your first option, They will invariably create,/leave you with an unreliable mess. Go the simple route where you have total contol instead.
(as Bill has suggested)
To make your grill you need only the simple tools, start with a box, hit n and add a radius and then delete most of it untill your left with the raduis part you want for one corner and it's adjacent sides.press f to flip it to face the other way (on the box it faced outwards to the curve, on the grill you want the polys to face inwards to the curve) and then move the part to a slight offset from centre. then mirror the peice on x then z to form all 4 corner edges and then patch in the top face by selecting points in order and in groups of 4 then pressing p to make polys, When you have patched all four corner peices with tops it will look like this
If you need to have various surfaces, this is a good time to select and name them before multiplying the part,
then array by 50 in x and z to create the grill, thats it done, unless you need it to have a matching geometry from the other side. if so..
next is a centred "rest on ground" and then mirror y and you get...
If you need an off set pattern, the shear tool will modify the cubic grill in seconds to give you the off set quickly or even this using the bend tool
And all in quads by default so you can subpatch it if needed.
Total construction time for all of the above (including 4 defined surfaces as top, inset row 1 and inset row 2 & end caps ) and capping the ends was 9 minutes.
Booleans lack control and make more mess than they are worth ;) The simple methods give more control and are generally quicker :tu:
15th February 2008, 06:22 AM
Wow, thank you all so much for your responses! BillS and jorjo, thank you for taking the time to post up some alternate methods of creating the grill. As soon as I get a chance, I'm going to try all of the methods out... like I said, I have soooo much to learn, and I learn best by "doing"... These walk-throughs will be a great help! :)
Will post up my results when I get some time...
15th February 2008, 12:40 PM
That grid response using small mesh 'bits' is a keeper. I have been using Stencil and then deleting the centers and merging (Shift-Z) the polys. Follow up with SmoothShift and bevel as needed.
I think I like Jorjo's method better though a Reduce Polys operation might be in order after the object is completed and don't forget an 'M'
15th February 2008, 06:44 PM
The trick or experience part is just being able to see thing in their basic form. Then just reverse engineer it to figure out how to get back to the output as quick and easy as possible. Array and clone are great tools for making highly repetitive things like grills etc. Just figure out what the smallest, easiest piece is and start cloning.
16th February 2008, 03:04 PM
Well, after several false starts (due to my newbness, not the tutorials :p ) I finally got my grill constructed. I used jorjo's method and here is what I came up with... I'm still going to do Bill's version, as I know I will also learn alot from it, as well!
Thanks, again for the great assistance, guys! :)
16th February 2008, 03:29 PM
Job well done; everyone.
16th February 2008, 05:51 PM
Look at it this way. Your not likely to forget how to do this anytime soon! :) Looks great!