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## 3ds Max / 3ds Max Design General

Contributor
Posts: 12
Registered: ‎05-02-2009

# I can't get the bend modifier to work right.

148 Views, 3 Replies
11-25-2010 10:07 AM
I made a simple tube with these dimensions. 256 outside, 240 inside, 512 height. I have the grid setup on 8. Everything lines up right on the grid. However when I add a bend modifier, at either 45 or 90 degrees it no longer lines up correctly. Even if I use snap to grid it doesn't line up. Do I need to change the size to get it to line up with the grid. I want bot ends of the tube to line up.
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Posts: 18,859
Registered: ‎08-07-2007

# Re: I can't get the bend modifier to work right.

11-25-2010 11:33 AM in reply to: kobaltic
First things first - 256 what? Max's default is Inches - did you really intend a pipe nigh on 21 feet across?

Next up - 45 or 90 degrees. To have the ends "line up", be parallel, you'll need 180 degrees.

Snaps won't be of much help - you are parametrically altering the underlying mesh so there's nothing to snap to.

I suspect that you didn't increase the number of Height Segments. Bend works by calculating the required positions of the existing vertices - if there aren't enough the the bend won't be smooth at all and the ends won't end up where you expect them to.

Finally, if you bend it 180 degrees you'll form a semi-circle (viewed from the side). Imagine the centre line of the tube starting at the origin. Circumference of a circle is 2 * PI * Radius. You have half a circle, so half of that, or PI * R. You know half the circumference, it's the height of your tube, 512. Radius will therefore be 512 / PI which is (roughly) 162.954 so there's no way the centre line will end up on the grid. You'd have to work the maths backwards, starting from the required Radius to calculate the initial height of your tube.

Max 4.2 through 2015 (SP2+EXT1), Composite 2014.
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 335.23).

Contributor
Posts: 12
Registered: ‎05-02-2009

# Re: I can't get the bend modifier to work right.

11-25-2010 12:04 PM in reply to: kobaltic
I tried both 45 and 90. I have the units set to 2.54 centimeters. This makes the grid the same as UDK. It is going to be a tunnel but I want some bends in it. I increased the height segments to 10.

Thanks for the tips. I will look into it.
Moderator
Posts: 18,859
Registered: ‎08-07-2007

# Re: I can't get the bend modifier to work right.

11-25-2010 12:26 PM in reply to: kobaltic
Ok, I'll bite - why 2.54cm? Why not change the System Units to cm and be done with it? Converting between Metric and Imperial, system vs display units, is not recommended - at least have both metric or both imperial.

Working on a grid set to 8's make me suspect there's a game involved here, in which case feel free, but if you're modelling real life objects then the advice is always to model them to scale and set the grid appropriately (10 for metric, probably 12 for imperial (inches/feet)).

Max 4.2 through 2015 (SP2+EXT1), Composite 2014.
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 335.23).