Zero out center points
Up to this stage, I've mainly been working with one half of the model and using the Duplicate Special tool to create an instance for the opposite side. Now is the time to create a single unified mesh. Start by deleting the duplicated half. Next, in the Front view, select all the vertices that run down the center and in the Status Bar, set the Input line menu of operations to Absolute transform. With the vertices still selected, punch a 0 into the X channel for the Absolute transform. This should snap the vertices perfectly to the center line. Another quick way to select all the vertices on the center line is to double click an edge to select the entire loop, hold down the Ctrl+RMB and when the marking menu appears, select To Vertices.
Using the Absolute transform to make sure the center vertices are aligned perfectly
Duplicate, mirror and invert the normals
Now to duplicate the model to the other side. First make sure the objects pivot is at the world center. If not, select the object and activate the Move tool (W). Then hit the Insert key on the keyboard to allow for editing the pivot location. Hold down the X key to enable Grid Snapping and drag it to the world origin. Hit Insert to come out of the pivot editing mode. You can also hold down the keyboard D key to edit the position of the pivot. With the pivot in the correct place, select the mesh and hit Ctrl+D to duplicate the model. In the Channel Box for the duplicated mesh, pop a -1 into the Scale X to flip the model to the other side.
With the duplicated mesh still selected, go Modify > Freeze Transforms to clean out the Channel Box. If you are using Maya 2014, the normals for the mesh will be inverted for you, which is what we want to happen. If you are using any version of Maya prior to 2014, select the duplicated mesh and in the Polygons Menu, go Normals > Reverse. You can view the normal of any object by selecting it and going Display > Polygons > Face Normals.
Creating the other side and freezing the transforms
Merge center vertices and soften edges
Now select both halves of the model and go Mesh > Combine to create one mesh. The vertices down the center will now need to be merged together. Select them all using the previous method as described in step 6 and go Edit Mesh > Merge (Options). Set the Threshold to 0.0001 and hit Apply. You may notice a hard edge running down the mesh where the 2 halves have been merged. To get rid of this, select the model and go Normals > Soften Edge.
Getting rid of the hard edge running down the model with the Soften Edge tool
Scale to size and tidy up
We now want to scale our character to some real-world units. I am going to presume this fella is around 6-feet tall, which works out at around 182.88cm. Go Create > Measure Tools > Distance Tool and create 2 locators, one at the base and one at the tip of the head. The distanceDimension1 node should inform you of the height. Now take the second locator (positioned at the head) and translate it upwards until the distanceDimension1 node reads to a value of approximately 188cm. Then select the mesh and scale it uniformly to meet the locator and match the height. The last thing we need to do is select the model and go Edit > Delete By Type > History, followed by Modify > Freeze Transforms. The model should now be ready to move to the next department.
Scaling the character to a height of approximately 6-foot and making sure the mesh is clean
Top tip: Checking for inverted normals
Here is a quick way in Maya to check if any face normals are inverted. In the viewport menu, go to Lighting and disable Two Sided Lighting. If any faces turn black (inverted normal), select them and go Normals > Reverse.
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Disable Two Sided Lighting to check the normals