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View Full Version : Select polys at the same level/altitude?



vector
10-21-2015, 01:18 AM
HI

I have an imported stl mesh from a terrain with water. I need to select all the polys at the same level (water) but since there are thousand of polys it's very difficult to do that without selecting terrain ones. How do you select all that polys? Time ago we have a box selector in modeler will work nice for that task...

Thanks

vector
10-21-2015, 01:55 AM
In my case I found 'select by normal' helps although a few polys must be unselected

Danner
10-21-2015, 03:29 AM
The box selector you are talking about is probably what is called "volume" but it's not really a selector.. it's more like an area of influence. (at least visually no normals get activated)

Ztreem
10-21-2015, 04:05 AM
The box selector you are talking about is probably what is called "volume" but it's not really a selector.. it's more like an area of influence. (at least visually no normals get activated)

Yes, it's called volume and even if it not shows what selected you can manipulate the polys inside the volume with most tools.

JoePoe
10-21-2015, 07:45 AM
Perhaps this.... Custom Select (https://www.lightwave3d.com/assets/plugins/entry/custom-select/).

There's a Distance setting/option.

jeric_synergy
10-21-2015, 05:27 PM
In case one has forgotten:

To use VOLUME SELECT to select, you can drag out the box in 3D in two vuports, and then use the STATS panel (!!!) to Select/Deselect. Nothing will appear to happen, but the entities are selected when you go to their mode. If you just make the box and apply a tool, the items inside are considered to be Selected, although there's no visual indication of this. (Experiment, it's not difficult.)

For POLYS, there are two modes: one affects polys that are entirely inside the volume, the other does that PLUS polys that straddle the border. You switch between the two modes by clicking VOLUME repeatedly. The modes are denoted by the appearance of the border, dotted or solid.

Note that often it is easier to select the INVERSE of the desired Selection, and then invert the Selection, and/or use Shrink/Expand Selection.
++++++++++
(here's the good tip for the OP):
One trick to selection is to make a dummy Endomorph and distort your object in a way that makes selection easier: for instance, you may want to exaggerate the vertical scale to isolate the "sea level" points/polys. This is much easier once you've multiplied the difference in elevation by a factor of ten.

Always remember to make a Selection Set or Part if you've made a particularly difficult Selection-- you'll thank yourself later. Hotkey CREATE PART to make it easier. Also, while there is no "Add To Part", CREATE PART fills that function (yeah, confusing). Remember polys can only be in ONE Part at a time, while Points can be members of multiple Selection Sets.