Display Face Normals

Display Face Normals

Maya 2012 Tutorial


How to Display Maya Polygon Object Face Normals



The direction of the face normals specifies which faces are pointing forward. Normals are also used to calculate smooth shading for two connected faces. By default if the angle between two faces is less than 30 degrees, the joining edge appears rounded.

In this example, we will create a cylinder and reverse some of it's faces. The object will be converted to a one sided object before rendering so you can see what happens if you have a reversed face.

To correct an object with reversed faces, select the backwards faces and choose Normals > Reverse from the Polygons menu set.


Step One

Add a polygon cylinder to the workspace by choosing Create > Polygon Primitive > Cylinder (include options).

Step Two

In the options, set the Axis Divisions to 6. Click the Create button to add your cylinder.

Step Three

To view the object normals, select the object and choose Display > Polygons > Face Normals. A normal line appears in the middle of each of the object's faces.

Step Four

To adjust the normal size, choose Display > Polygons > Normals Size.

Step Five

Tumble your object in the perspective view (Option/left mouse drag (PC - Alt/left mouse drag) and notice that all the normals are pointing outward to indicate that the front faces are pointing out.

Step Six

Right-click the cylinder and choose Face.

Step Seven

Click one of the top faces, then Shift click every other face on the top of the cylinder. You should have three faces selected. To activate Smooth Shade view, press the 5 key.

Step Eight

Choose Normals > Reverse from the Polygons menu set. The normals for the selected faces now point in the down direction.

Step Nine

Render your scene by clicking the Render Current Frame icon. The object should look fine.

Step Ten

Right-click the cylinder and choose Object Mode, then select the cylinder.

Step Eleven

Open the Attribute Editor, pCylinderShape tab and click the Render Stats section.

Step Twelve

Deselect the Double Sided checkbox and click the Render Current Frame icon. Some of the object faces are no longer visible because they are reversed.

Display Normals for New Objects

You can activate normals for all new objects by choosing Maya > Preferences > Polygon section. In the Faces section, check Normals.

Disable Normals

To turn off the object normals, select your object and choose Display > Polygons > Face Normals.