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Topic: Another Pivot Question  (Read 8864 times)

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May 07, 2015, 12:36:51 pm
Kevjon,
Quote
Andrei, thanks, I like the first option. But doesn't work for me the manipulator ends up at the scene origin rather than aligned to the face selection. I assume this is because I've mucked around with the pivot and manipulator so much that I get a different result. This would also happen on a real project rather than just a scene with one cylinder.
If you press F2:
1. Click in any free sapce it will set pivot to world origin
2. If you click LMB+RMB it will set pivot to center of selection.

Also:
3. If you press LMB it will set not only POsition but Orientation too.

I made video:
http://take.ms/mcoue
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  • Spline
May 07, 2015, 07:09:31 pm
There is no such thing as "Manual Pivot"
"Pivot" and "manipulator" are not the same.
Just use "Set manipulator" when dealing with manipulator, it will save confusion.

Steve could you give me some advice here? As I only model very simple objects in Nvil and never build complex scenes with numerous objects/meshes/instances I believe I could come along completely without using the dual concept of Pivot and Manipulator. Do you see a way to only reposition/orient the Manipulator and to essentially deactivate the influence of Pivots? Is there a function which makes the Manipulator position always be the Pivot as well?

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May 08, 2015, 08:34:11 am
Kevjon,
Quote
Andrei, thanks, I like the first option. But doesn't work for me the manipulator ends up at the scene origin rather than aligned to the face selection. I assume this is because I've mucked around with the pivot and manipulator so much that I get a different result. This would also happen on a real project rather than just a scene with one cylinder.
If you press F2:
1. Click in any free sapce it will set pivot to world origin
2. If you click LMB+RMB it will set pivot to center of selection.

Also:
3. If you press LMB it will set not only POsition but Orientation too.

I made video:
http://take.ms/mcoue

Thankyou Andrei, thats brilliant and going to save me a lot of time trying to orientate myself in 3D space !

At first I couldn't get it to work like you showed in the video.

Just incase others have the same problem, you need to make sure polygons snap is on or else you'll get different results than Andrei shows.
« Last Edit: May 08, 2015, 08:41:40 am by kevjon »

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May 08, 2015, 08:42:30 am
Yes you have to enable snap options like, vertex or polygons to make Set Pivot tools to know where to snap.
Portfolio: www.samardac.com

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May 08, 2015, 01:30:58 pm
Hi polyxo,

Steve could you give me some advice here? As I only model very simple objects in Nvil and never build complex scenes with numerous objects/meshes/instances I believe I could come along completely without using the dual concept of Pivot and Manipulator. Do you see a way to only reposition/orient the Manipulator and to essentially deactivate the influence of Pivots? Is there a function which makes the Manipulator position always be the Pivot as well?

From an end-user point of view, the object/mesh pivot should be nothing more that a reference point for the object/mesh position/orientation. But due to tools/functions to move that objects pivot, and tools/function that use that objects/mesh pivot, it adds to confusion.

If we go back several years, Nvil was "Voidworld" and Voidworld was also an animation programme. In animation programmes you can have bone structures that are set in a parent>child relationship. Each bone would then have a pivot point set between parent/child. So there was a need for each object to have its own pivot, and for the user to be able to set that pivot to correct location.
We can also look at why Nvil as "Objects " and "Mesh". Again years ago, when creating an object for animation there was a need to split that object into separate mesh. Each mesh would then be assigned to a bone, that bone would then influence that mesh in animation. [Of course, it no longer works that way, we now (and for several years) have single (uni-) mesh, and it is polygon groups that are assigned to bones(with weights)]
So why still have "object/mesh pivots" and "Mesh" in a modeling programme? Only reason I can see is due to legacy implementation and IStonia not making change.

When using "Manipulator" there are options that control its current position/orientation, they are put forward such as "Object", "Selection", "Manual" etc. When the manipulator position/orientation is set to "Object", the manipulator moves to selected object pivot location/orientation. That does not make the manipulator the objects pivot, it only makes the manipulator adopt the objects pivot location/orientation. Of course, the manipulator acts as a pivot-point for rotation, but still, it is not the object_pivot.

So from end_user point of view, forget about "pivot" unless you use tools/function that require it.


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  • Spline
May 08, 2015, 04:53:17 pm
Thank you Steve for this thoughtful explanation – I'm sure this info it's also helpful for others.
Admittedly I was already aware of most of the theory – only the practical part gets badly in the way :). Indeed having this duplication is one of my mayor gripes with Nvil:
I have always avoided modelling inside animation programs, because one inevitably has to deal with convoluted object handling strategies which were designed for animation – even if one doesn't want to animate at all. Now in Nvil we couldn't even animate, even if one wanted to...


On the practical part of avoiding to ever touch pivots...
What commands do require setting them up? I would guess instancing/arraying submeshes of objects, what else?


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May 08, 2015, 08:20:29 pm
Good post Steve, thanks.

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May 09, 2015, 09:01:24 am
Hi Kevjon,

.............so I generally work in a precise way ......

I do not want to make this more complicated, but you need to be aware.

If we use your first post as example. You show a cylinder with end polygon selected. You are then using tool/function to move manipulator to polygon selection. If you use "Snap > Polygon Center" or "Set manipulator > LMB+RMB", by default, the manipulator will move to selections geometry center. If you actually want to move to "Bounded box" center, you need to enable option  "Edit > Options > Subobject Selection Center Is Bounded Box Center"

For objects position. If manipulator is set to position "Object", the manipulator will move to selected objects Pivot location. If manipulator set to "Selection", manipulator will move to selected objects bounded box center.

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May 09, 2015, 09:27:09 am
Hi polyxo,

On the practical part of avoiding to ever touch pivots...
What commands do require setting them up? I would guess instancing/arraying submeshes of objects, what else?

The instance creation tools, they do not directly use object pivot.
Instance > Array: Uses objects bounded box center for position and current manipulator orientation for direction.
Instance > Radial: Uses manipulator by default, but has option to use object pivot
Instance > Spline: Uses world origin.

Sub_meshes: They are supposed to have their own pivot, but attempting to access or control them is problematic. Maybe the mesh pivots where fully controllable at one time, but now they just add to confusion.

I am not sure what uses object pivot, I would need to find time to check. My current config/workflow avoids various tools/functions because of (various) issues.

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May 09, 2015, 11:53:20 am
Hi Kevjon,

.............so I generally work in a precise way ......

I do not want to make this more complicated, but you need to be aware.

If we use your first post as example. You show a cylinder with end polygon selected. You are then using tool/function to move manipulator to polygon selection. If you use "Snap > Polygon Center" or "Set manipulator > LMB+RMB", by default, the manipulator will move to selections geometry center. If you actually want to move to "Bounded box" center, you need to enable option  "Edit > Options > Subobject Selection Center Is Bounded Box Center"

For objects position. If manipulator is set to position "Object", the manipulator will move to selected objects Pivot location. If manipulator set to "Selection", manipulator will move to selected objects bounded box center.

Thanks Steve, very handy info.

In practice, I found locating and orientating the manipulator, pivot to complicated between subobject/object modes. I wrote my first composite tool to align the workplane to the selection, make it active and set the view to top, set the manipulator orientation and position to world. I need this to align a lot of rigging wires on a WWI fighter aircraft I'm working on. Each rigging wire has several mesh items and they are trick to align with struts and other parts of the airframe.

You post to polyxo on instances Ive copied for future use. Very useful info there also.
« Last Edit: May 09, 2015, 12:21:02 pm by kevjon »

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May 09, 2015, 12:14:53 pm
Thank you Steve!

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May 09, 2015, 12:26:23 pm
I wrote my first composite tool to align the workplane to the selection, make it active and set the view to top, set the manipulator orientation and position to world.

You will still have the same issue between "Geometry center" and "Bounded box center"

An example to help explain.

Here I have a default Cylinder primitive, with top polygons selected. The geometry is evenly spaced/symmetrical. So when calling "Set manipulator > LMB+RMB" or "Workplane > Align to selection", by default, the manipulator/workplane will move to geometry center. But because geometry is evenly spaced/symmetrical, the result will be center of the outer circle of selection, and will be what is expected.



If I add extra geometry to cylinder, in this case edge_loops to some edges, then call those tools again. You will see, by default, the result is probably not as expected, as the workplane/manipulator is at geometry center, and the geometry is not evenly spaced/symmetrical.



I am just making sure you are aware of this, as it can confuse at times.





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May 09, 2015, 01:07:32 pm
Thanks for that, I never considered that problem. It is a likely scenario in a real model.

Like most things in 3D, complicated.

I just tested my workplane composite tool with this checked and works as expected now. Great Tip about turning this on. "Edit > Options > Subobject Selection Center Is Bounded Box Center" ?