topic Re: Align object's pivot to object's orientation in 3ds Max Programming Forum

Align object's pivot to object's orientation

kenc — Fri, 22 Mar 2024 02:37:28 GMT

I have a DXF from Softplan that I import into max. When the objects come in they all have the same pivot rotation orientation. I then center the pivots to each object's center as seen in image1.jpg

What I need to do is by maxscript is to align the object's pivot to the object's orientation. In image2.jpg the pivot for an object does not align with the object but rather at 45 degrees.

In image3.jpg this is how I need to rotate the pivot to align with the object.

Help would be much appreciated.

TIA

Re: Align object's pivot to object's orientation

denisT.MaxDoctor — Fri, 22 Mar 2024 21:16:37 GMT

Is only DXF format available for export from Softplan?
If we are talking about AutoCAD DXF, there should be no problem with pivot (tm) orientation.

Re: Align object's pivot to object's orientation

kenc — Fri, 22 Mar 2024 21:25:14 GMT

it is exported directly from softplan. I just asked the cad guys to export to 3ds and fbx

Re: Align object's pivot to object's orientation

denisT.MaxDoctor — Fri, 22 Mar 2024 21:26:23 GMT

Usually, the "oriented bounding box" method is used to solve this problem. As far as I know, there is no built-in solution for this, but I remember some scripts to do the job.

For 2D case, the script is quite simple.

Re: Align object's pivot to object's orientation

denisT.MaxDoctor — Fri, 22 Mar 2024 21:28:35 GMT

What other formats the Softplan can export? Can it do FBX?

Re: Align object's pivot to object's orientation

kenc — Fri, 22 Mar 2024 21:34:38 GMT

@denisT.MaxDoctor no FBX. Also has 3ds which is no good all the meshes are called "Mesh". Checking DWG now

Re: Align object's pivot to object's orientation

kenc — Fri, 22 Mar 2024 21:49:13 GMT

@denisT.MaxDoctor DWG and DXF output exactly the same thing

Re: Align object's pivot to object's orientation

leeminardi — Fri, 22 Mar 2024 22:17:16 GMT

What happens when you use Akign to object?

Are the object composed of lines or 2d, or 3D objects.

A simple script could be used that prompts the user to specify a pivot origin, a point on the x axis, and a point on the xy plane and then reorient the pivot and center it. Would this be acceptable?

Re: Align object's pivot to object's orientation

kenc — Fri, 22 Mar 2024 23:25:13 GMT

@leeminardi this needs to be run by maxscript. No user input.

The Align To Object does not work

Re: Align object's pivot to object's orientation

leeminardi — Sat, 23 Mar 2024 00:21:20 GMT

Can you post a sample dxf file?

Re: Align object's pivot to object's orientation

klvnk — Sat, 23 Mar 2024 11:02:45 GMT

getting a tight object aligned bounding box and therefore it's "orientation"/pivot for all general cases is a non trivial operation. Though in special cases it maybe easier.

Re: Align object's pivot to object's orientation

istan — Sat, 23 Mar 2024 11:23:52 GMT

@klvnk wrote:
Though in special cases it maybe easier.

In this particular case, when objects always look like in image1 (a "thin" object), at least one vector could be easily aligned per MXS.

Re: Align object's pivot to object's orientation

leeminardi — Sat, 23 Mar 2024 13:22:14 GMT

It looks like the application is related to cabinetry and therefore the pivot Z axis is correct. So yes, only one vector is needed to define orientation. A sample file would be helpful. Searching for consecutive vertices that have the same z coordinate may be sufficient to determine the vector.

Re: Align object's pivot to object's orientation

kenc — Sat, 23 Mar 2024 17:01:21 GMT

@leeminardi actually it's an entire house. The items in my screenshots are the kitchen cabinets.

I'm not at the office but I will remote in and get the dxf.

Re: Align object's pivot to object's orientation

leeminardi — Sat, 23 Mar 2024 18:01:19 GMT

I created a couple of "panels" (boxes) in AutoCAD and determined that the first two vertices could be used to define the orientation of the pivot.

Try the following program and let me know how it works on your file.

-- Modifies selected object pivots such that their -- first two vertices define the local x axis and -- the local z axis is in the world z axis direction. obj = selection for o in obj do ( v1 = getVert o 1 v2 = getVert o 2 xaxis = normalize(v2 - v1) yaxis = normalize(cross [0,0,1] xaxis) a = acos(dot [1,0,0] yaxis) o.transform = o.transform * (RotateZMatrix a) resetxform o maxOps.CollapseNodeTo o 1 true o.transform = o.transform * (RotateZMatrix -a) )

Re: Align object's pivot to object's orientation

kenc — Sat, 23 Mar 2024 20:34:41 GMT

@leeminardi apparently all our servers are under maintenance this weekend so I can't upload the dxf till Monday.

I will try out your script.

How do I rotate just the pivot of an object without rotating the object?

Re: Align object's pivot to object's orientation

leeminardi — Sat, 23 Mar 2024 20:37:50 GMT

@kenc wrote:

How do I rotate just the pivot of an object without rotating the object?

Re: Align object's pivot to object's orientation

kenc — Sat, 23 Mar 2024 20:48:03 GMT

Sorry I should have been more specific. Rotate the pivot with maxscript.

Everything I do is by maxscript only.

Re: Align object's pivot to object's orientation

leeminardi — Sat, 23 Mar 2024 21:02:03 GMT

I do it by rotating the object orthogonal to the world reset the transform and rotate the object back.

Take a look at my code.

[Edit]

Since in your case we just need to rotate about the z axis we can use a z-axis matrix rotation. If the rotation were more complex you would have to use quats.

Re: Align object's pivot to object's orientation

istan — Sat, 23 Mar 2024 23:23:00 GMT

@leeminardi wrote:
If the rotation were more complex you would have to use quats.

Remark: there's no need to use quats, if you would omit using angle values in your calculation.. there exists another solution using simple matrix calculations 😉