boolean problems

[Andrew Blair]

I'm attempting to make an I-beam, but whenever I attempt to boolean more than 1 cylinder out of my rectangle (or extruded shape) it doesn't fill in the insides of the rectangle. It just cuts a circle out of the inside of the box and thats it. help me please!!!!!

[kcy88]

Could you post a screenshot?

[Andrew Blair]

This is what happens here. rather annoying, but i think it's because my box doesn't have enough segments.

[Alexander McGee]

Simple solution: add a 2-sided material to the object. That will usually fix the problem.

This generally occurs because of the way you are doing the boolean. Try doing them in a different order, or grouping all the negatives into a single mesh.

Hope this helps..

[rowe]

Are you using 3ds max 7? If so, there should be an option called bridge (by the extrude) on the editable poly options rollout. I tend to avoid booleans for making shapes because the are imprecise. How I would go about making your I beam would be to use the cylinder to cut -> refine the box (in the boolean options) instead of subtracting from it. Then I would convert the whole thing into a editable poly and use the bridge option to make the holes. If the cylinder doesn't come out smooth, use a polyselect modifier to select the polys in the cylinder and the smooth modifier smooth them out. Hope that helps

[kcy88]

Depending on the complexity of the object you want to put holes in, boolean can really be messy. However, if it's just putting holes in a simple rectangular cube, I'd use boolean.

Here's how:
1) Divide the polygons on each side of Operand A, the object you want holes in, so that each (in this case) cylinder will cut through a polygon and not all three cutting into one polygon. screenshot (http://home.earthlink.net/~kcy88/Boolean/HolesBoolean01.jpg)

In my scene, I selected the top and bottom edges on both side and used CONNECT to divide the polygon. Next I used Inset.

2) Create the cylinders and COPY and INSTANCE the number of cylidners you want. In my scene I set the height segment to 1 and SIDES to 20. Then, select all the cylinders and convert them to Editable Polygon. Select one of them and ATTACH the others. Now you have one object instead of three; this will create a cleaner cut in the cube.

3) Finally, select the cube and choose Boolean. Select the cylinders for your Operand B. and It should come out like this (http://home.earthlink.net/~kcy88/Boolean/HolesBoolean02.jpg).
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Another method of making holes is TESSELATING a polygon, COLLAPSING it, select the center vertex, CHAMFER it. Select the center polygon on both side and BRIDGE.
Here are some screenshots:
one (http://home.earthlink.net/~kcy88/Boolean/Holes01.jpg)
two (http://home.earthlink.net/~kcy88/Boolean/Holes02.jpg)
three (http://home.earthlink.net/~kcy88/Boolean/Holes03.jpg)
four (http://home.earthlink.net/~kcy88/Boolean/Holes04.jpg)
(ignore the three cubes below the main object :) )

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-kevin

[Andrew Blair]

Thanks guys. For what i'm doing right now, which is just working with IK, converting all the objects to an editable poly, then attaching them together & booleaning works just fine. thanks for the help. If I end up making a refined model, I may use bridge-smooth, etc.