[3DSMax] Volume Select Modifier + Animated Object = random

xXm0RpH3usXx

Dear polycount community,

I am currently experimenting with pushing an animated box over a plane.
The ultimate goal would be to have all of the faces inside have a different material ID.

For this I set up my plane as follows:
(order is like in the max modifier panel)

[Material ID] (<- set to 2)
[Volume Select] (<- set to use the box as face selection)
[Base Object] (<- in this case a plane with a lot of subdivisions)
(obviously I put a multi-sub map on it)

Problem:
When scrubbing the timeline random faces are not properly selected. Also returning to a frame which had a problem results in a different random selection.

In this example I put a "delete mesh" modifier instead of the material id one, to examplify the case:

Using the vertex option does result in a clean selection, the problem however is that the "Material ID" modifier only works with a face selection.

And I havent found a solution to parametrically change the vertex selection to a face one every frame. ("get stack selection" in the edit poly modifier only gets the initial selection on the first frame and doesnt reload on scrubbing)

Did anyone encounter the same problem? Is it 2015 specific? Is there any workaround?

Thanks in advance

spacefrog

I found this to happen too when using the face level selection in volume select. I could reproduce it with every Gizmo method, even if i choose a second geometry to select the faces: there are always stray faces selected.
Vertex level selection works as expected. I suspect it being a bug in the modifier. BTW: it happened in Max 2014 too, so it is'nt Max 2015 specific.
I just tested in 3ds Max 2016 SP2 and the problem seems to be fixed there

xXm0RpH3usXx

I dont even have 2016 myself, so thats not an option for me.
Also I wouldnt want the script I am working on to only work on that one version.

It's really a shame, I would have thought this is a pretty frequently used technique, there's a bunch of good uses for an animted volume select!

I did a test, putting three copies of the volume select modifier on top of eachother and putting the selection method to "add" seems to select all of the faces.
But honestly, this is not an ideal solution, either. As i want to add a few more selectionobjects in there.
So 3 selection objects would mean 9 modifiers, this will take too much memory in the end.

Eric Chadwick

A few years ago there was a bug when using Vol Select in vertex mode, where it would randomly select solitary vertices at full strength. This was for a pre-rendered animation. Solved it by adding a Relax on top. Not sure if that helps or not.

xXm0RpH3usXx

no, unfortunately this does not work.
however, if i put an editable mesh modifier on top of the volume select and change the subobject mode to face i get all of them, even those that where not selected.

thanks for testing and helping, too bad it didnt work out