Intro

Due to different types of products having different overall shape, centering/positioning in the scene should be done specifically for each type.
Correctly centered models will ensure correct look when rendered and published, not only for SD (360 viewer) but also for AR, studio or wherever the model might be used.

Types of products and positioning inside a 3D scene

There are numerous types of products such as two seaters, 3 seaters ,recliners, armchairs, dining chairs, sectionals etc.  In almost all cases the positioning is always done by the lowest element of the model, such as glides or legs.  Exceptions are some types of products where the positioning should be done as a group of all elements (bounding box).

Please check the following list of types of objects and how positioning should be done:

• Sofa 3 seater/Sofa 2 seater/Armchairs/Ottomans/Dining chairs- these products contain legs or glides most of the time and the positioning should be done according to the legs or glides.
  In case these products do not contain legs or glides the positioning is done as a bounding box (group).
• The sectional products (e.g. 3 STR + LAF Chaise, 3 STR + Corner + 2 STR, etc.) or furniture sets (dining table + 4 dining chair, outdoor 3 STR + ottoman + coffee table, etc.) need to be considered as a single product when these are to be centered, meaning that these will be centered as a group (bounding box).
• Office chairs/Swivels/Products with rotating legs should be centered according to the middle vertical leg/cylinder 

Positioning using the modeling panel

Before the positioning is initiated, make sure that:

• No hidden elements are present in the scene
• Unlink elements if linked elements are present such as stitches - in order to avoid flipped elements later
  

After the above is confirmed:

1.Select “Glides” or “Legs” in case of Sofa 3STR/2STR/Armchair/Dining Chair/Cabinet containing legs.

2.Press the “Center” button

3.Press the “Set” button-By doing this the panel automatically centers the model in the center of the scene and sets the pivot of all elements at  0,0,0 (X,Y,Z). 

4.Press the “Non Zero Transforms” and “Fix” button -this will reset the rotation of the pivot  0,0,0 (X,Y,Z)

Continue until the final step “Names and Scene Structure”. Before you get to this final  step all previously unlinked elements should be linked back to their respective parent elements.

Please check the following video (narrated example)
You can also check older non narrated example here

Modeling panel positioning steps

Reset Non Zero Transforms

Manual Positioning

Manual positioning is similar to the positioning done through the panel but there are few extra steps that need to be done.  Even though it is a more complicated procedure than the one using the modeling panel it is safer and more accurate and ensures that there are no flipped elements.

Before the positioning is initiated, make sure that:

• No hidden elements are present in the scene
• Unlink elements if linked elements are present such as stitches - in order to avoid flipped elements later

After the above is confirmed:

• Select all elements in the scene
  
  
• Go to the “Hierarchy Tab”, select the “Affect Pivot Only” and press the “Center to Object”. This will place the pivot in the center of each element.  Uncheck the “Affect Pivot Only” afterwards.

Centering the pivots of elements

• With all elements still selected, deselect the “Glides” only and link all the other elements to the Glides.
  
  
• Select the “Glides’ , and change  the X and Y position  to 0  (move -> type in 0 for X, and 0 for Y). This will center the model in the scene.

Centering the model

• Unlink all elements and select all once again.
  
  
• Go to the “Hierarchy Tab” and select “Affect Pivot Only” and set the position of the pivots to 0,0,0 (X,Y,Z). After that convert to editable poly.
  
  
• Go to the “Hierarchy Tab” and select “Affect Pivot Only” again and set the rotation  of the pivots to 0,0,0 (X,Y,Z). Convert to editable poly once again.
  
  
• Select all elements again, go to the “Utilities” tab, and apply “Reset XForm”.  After that convert to “Editable Poly” again to collapse the Reset XForm.

Reset XForm

• With all elements selected, go to “Modify” tab and from the modifiers list apply:
  
  
  • Normal 
  • Normal
  • Smooth - set the smoothing groups to channel 1.

Fixing the normals and setting smoothing groups to a single channel

• Convert to editable poly in order to collapse the modifiers from step 9.
• Link previously unlinked elements to their respective parents.

When this procedure is picked for positioning the models, when the checking is done with the modeling panel you can skip the “Center” and “Unify Normals” options.

Skipping "Center" and "Unify Normals" if the centering procedure is done manually

Please check the following example.

Swivel/Star Legs positioning

The positioning of these types of products is better to be done manually.  Positioning is done according to the middle vertical leg/cylinder.

Please check the following video.

Conclusion

Due to numerous issues lately with floating elements on the models when rendered, such as stitches, please utilize the manual option for positioning and resetting transforms which is safer to avoid issues such as the above mentioned. Do not utilize the panel's "Center" and "Non-zero Transforms". The "Unify Normals" option can also be omitted, replacing it with manually applied "Smooth" modifier (on top of Normal modifier doubled) with smoothing groups set to channel 1.  This setting should work if the models are properly modeled. 

Please check the manual video tutorial in the link below, which describes the manual centering of a product, manually resetting transforms, and manual smoothing groups and normals setting. Please make sure to maintain the checkup order in the modeling panel in the exact order as described in the video.
Utilize the manual approach for all types of products.

Manual centering and resetting transforms.