Centering at the Origin

Why is centering your model to the origin important? Having the model at the origin creates less confusion for customers who will likely be merging the model into another scene with other models. They will know exactly where the model will come in. Models not placed at the origin could merge into a scene and become difficult to find or edit depending on its imported position.

CheckMate Pro LogoPSLogo For CheckMate Pro (2.4.1) and PixelSquid (2.3.1) certification, you are required to have the pivot point of the model centered on the 0, 0, 0 origin.

Model Centered at Origin (model by cgeas)

Model Properly aligned on import (plane model by 3d_molier)

Model Properly aligned on import (plane model by 3d_molier)

Model not properly oriented (hangar by Giimann)

Model not properly oriented on import (hangar model by Giimann)

Moreover, the model must also sit on, or be slightly above the ground plane with the obvious up-axis of the model aligned with the World up-axis in your 3d application. In other words, the model should not be lying on its side, skewed in an odd direction, be upside-down or sit below the ground plane when opened.


Both Orientations are Correct (models by 3DEnvironmentModels and yaschan)

Both Orientations are Correct (models by 3DEnvironmentModels and yaschan)

NOTE
There are several object types that can have multiple valid up-axes. Things like books, pencils, crates and balls, among others can easily be aligned in different ways, and all of them can be considered correct. In these cases, the artist is allowed to choose which way they want the object to be oriented by default in the scene. But it is important that you indicate your chosen up-axis via your product imagery so a customer knows what to expect when they import your model into their scene.
CheckMate Pro Logo Here are some general rules of thumb you need to follow for CheckMate Pro certification.
  • The base of the model should sit on or just above the ground plane.
  • The model should be properly oriented to World up-axis – The obvious “up” side of the model must be pointing toward the World up axis.
  • The model must be in the same position and framing as the Signature and Context Signature images.

Setting your Model on the Origin

All 3d applications will allow you to set your finished model at the Origin.


Single Object:

  1. Select your model.
  2. From the menu bar select Edit -> Transform Toolbox
  3. Within the Align Pivot set of controls, ensure Min is active and then hit the Z button to force the pivot to the base of the group bounding box.
Transform Toolbox

Transform Toolbox

This will move your pivot to the base of your model.

  1. Press the W-key to enter move mode, then hit the F12 button to bring up the Transform Type-in dialog.
  2. Within the Absolute:World side of the dialog, reset the X, Y and Z position to 0.0.
Transform Type-In

Transform Type-In

At this point, if you want to center the pivot again, under Align Pivot in the Transform Toolbox, click the Center button to move your pivot back to the center of your object.

Multiple Elements:

  1. If the model consists of multiple elements (like a car or helmet), be sure to Group everything first from the Group -> Group menu and name it appropriately.
Group Menu

Group Menu

  1. Open the group using the Group -> Open menu, then select the group object node directly (it’ll show up in pink in the main UI by default).
Open menu

Open Menu

  1. Next, go to the Hierarchy command panel and activate Affect Pivot Only for the group node. The pivot point should show up in the center of the bounding box for the model.
Affect Pivot Only

Affect Pivot Only

  1. From the main 3ds Max menu, go to Edit -> Transform Toolbox to open the small floating dialog.
  2. Within the Align Pivot set of controls, ensure Min is active and then hit the Z button to force the pivot to the base of the group bounding box.
Transform Toolbox

Transform Toolbox

Now that your group’s pivot point is properly placed, you can move the object to the origin above the ground plane.

  1. Deactivate the Affect Pivot Only button in the Hierarchy command panel.
  2. Press the W-key to enter move mode, then hit the F12 button to bring up the Transform Type-in dialog.
  3. Within the Absolute:World side of the dialog, reset the X, Y and Z position to 0.0.
Transform Type-In

Transform Type-In

At this point, your model should be centered on the origin and sitting on the ground plane.

Centering your pivot and ensuring it’s at the base of your model in Maya is a multi-step process. You first center the pivot, then determine the point on the model at which is the lowest on the Y-axis so that it sits on the ground plane properly. Once the pivot is positioned properly, then you can snap it to the origin and freeze your transforms.

Centering the Pivot:

  1. Select your model. If the model consists of multiple elements, use the Edit -> Group command to group everything, then ensure the Group node is selected in the Outliner.
  2. Select Modify from the top menu and select Center Pivot to relocate the pivot point to the center of the model.

Center Pivot

As you might expect, this will center the pivot to the center of the entire model, not just one element within in.

Moving the Pivot:

Now that you have the pivot centered, you’ll move it down on the Y-axis so that the model will sit properly on the ground plane. That means determining the lowest point on your geometry. In many cases, that won’t be simple to see, so a foolproof way is to create a temporary bounding box around your model and snap the pivot of your model to the bottom of that box.

  1. With the model selected, go to Modify -> Convert -> Geometry to Bounding Box [Options], and within the floating dialog ensure that One bounding box is selected and the Keep Original checkbox is active. Then hit Convert.
Convert_BBox_Dialog

Convert Geo to Bounding Box Dialog

This will create a bounding box that should surround your entire model. Now you can snap your pivot on the Y-axis to match the base of the new box.

  1. Select your model.
  2. Hit the Insert or D-key to go into Pivot mode on the model.
  3. Hold down the V-key (Snap to vertices), and dragging along the Y-axis only, snap the pivot to the base of the bounding box.
  4. Hit the Insert or D-key again to exit Pivot mode.
  5. Select the bounding box and delete it.

Your pivot point should now be aligned at the center of the model and at the very base now.

Centering to the Origin:

  1. Finally, click on the Move tool, hold down the X-key (Snap to Grids) and snap the model to the center of the grid. If the grid is not visible go to Display -> Grid to ensure you are snapping to the origin. 
  2. Once your model is centered at the origin, be sure to Freeze the Transforms.

  1. Select your objects and group them under a Null object.
  2. Select the Null object in the Object Manager.
  3. Go to your Mesh -> Axis Center -> Axis Center… option to bring up the Axis Center dialog.
AxisCenter_Menu

Axis Center Menu

  1. Click on the Enable Axis Manipulation button on the left of the CINEMA 4D viewports or by hitting the L-key so you can edit the position of the pivot for the Null object.
EnableAxisButton

Enable Axis

  1. Set the Action to Axis To, the Center to All Points, and make sure both the Include Children and Use All Objects checkboxes are active.
  2. Next, make sure that Alignment is active and the Axis is set to Y. In the center dialog, make sure the Y position is set to -100% (which will set the Null to the base of the model)
  3. Hit Execute.
AxisCenter_Dialog2

Axis Center Dialog

This combo will center the Null’s pivot to the exact center of the model on X and Z and will place it at the base of the model in the Y-axis. All that’s left is to center the model to the Origin.

  1. Deactivate the Enable Axis Manipulation tool (L-key shortcut), so that you can move the entire model.
  2. Zero out your X, Y and Z Position values.

At this point, your model will be safely centered at the origin.

In the Lightwave Modeler, you’re going to want to select all of your objects, then center them. That’s a pretty easy process.

  1. First, press the W-key on your keyboard to bring up the Statistics dialog
  2. Next, hit the Space Bar until you see Polygon Statistics at the top of this dialog.
  3. Press the + sign to the left of the word Total to select all of the Polygons in your scene file, then close the Polygon Statistics panel

Polygon Statistics Dialog

  1. Finally, press the F3-key to bring up the Rest on Ground dialog. 
  2. Make sure the Rest Axis is set to Y, and all Center Axes are checked as shown below, then hit OK. This will effectively center all of your geometry at the origin and cause the model to sit on the ground plane. 
LW_RestOnGround_Dialog

Rest on Ground Dialog


  1. Select your objects and group them under a Null object.

All Objects Selected

2. Right click to place the 3D cursor where you would like the models new center to be.

Placing the 3D Cursor

3. Then press Shift + Ctrl + Alt + C and click Set Origin to 3D Cursor.

Origin to 3D Cursor

4. Then go to the transforms panel and right click one of the transform values and click Reset All to default Value.

Reset All to Default Values