3. Simple Construction - A Diesel Loco - Part three


Version 1.1 - 28.June 2002

The chassis gets wheels

To create a wheel, we use a Standard Primitive again. This time a Cylinder. In the Left viewport, we click Cylinder in the Create toolbox. The parameters are shown.


We create the cylinder with the Keyboard Entry method rather the drag and drop method as we did with the box. We open the Keyboard Entry tool by clicking onto the small cross. The following parameters are now to be typed in:

  • Radius: 0.6 m
  • Height: 0.15 m
  • Height Segments: 1
  • Sides (number of polygones around the wheel, the tread): 18
  • Generate Mapping Coordinates must be selected.

One click on Create and here we are. The wheel is sticking halfway in the ground and is positioned in the middle of the virtual world. That doesn't matter yet. First, we have to convert the wheel into an editable mesh. As we did with the chassis, we rightclick onto the wheel and in the Quad menu we choose Convert to - Editable Mesh.


Hiding the chassis

The wheel is partly hidden by the chassis. Therefore we will hide the chassis temporarily. We select the chassis only and in the Display toolbox we click Hide Selected. The chassis is still existent but hidden.


To have the wheel shown as big as possible in all the viewports, we click Zoom Extents All within the view control. Doing this can also be achieved by pressing Ctrl-Shift-Z.


Now, we see the wheel in all viewports.


Setting the pivot point

In the front viewport, we see, that the pivot point of the wheel lies in the center of the world rather than in the center of the wheel. We have to change this in order to have the wheel positioned correctly.

To do so, we go to the Hierarchy toolbox and click Affect Pivot only, Center to Object and Align to World. Then we deselect Affect Pivot only.


Now, we can select and move the wheel. A rightclick onto the Move symbol opens the Transform-Type-In dialog. There we type in:

  • Absolute World X: 0.8 m (slightly more than half the track gauge)
  • Absolute World Y: 2 m (first wheelset, 2 meters in front of the center)
  • Absolute World Z: 0.6 m (Wheel is lifted by the radius' value)

Then, we click Zoom Extents All again.


If in perspective view, the wheel is not or only halfway visible, we use the zoom or focus tool in the view control.


Texturing the wheel

We open the Material Tool first. It might be empty. Gmax looses the material information once closed and reopened. Therefore, we have to get the material from the chassis. To make the chassis visible, we click Unhide All in the Display toolbox, select the chassis and in the material editor, we click the get! button. This gets the material from the current selection.

Then, we hide the chassis and select the wheel again. In the material editor, we click put, and this is the result:


The treads first...

In the polygon edit mode and front viewport, we select the tread of the wheel as shown in the image below.

The german text reads: Draw box from here... ...to there.


In the modifier list, we select UVW Map, the parameter X, and we click the Fit button.

Then we select Unwrap UVW and open the mapping editor.


With the Scale and Move tools, we map the treads to the light grey rectangle an the bottom right of the image.


Then we close the editor and collapse the modificator stack as usual.


...texturing the sides of the wheel

Again, we switch to polygon mode without clicking into any viewport. The tread polygones are still selected. We click the Hide button. The side polygones ought still be visible.


In the Perspective viewport we see, that the backfacing sides of the polygones are invisible. This is due to the direction of their normals. In the Front and Top viewport, all polygones are to be seen by their red edges.

Now, we select all visible polygones by dragging a box around them, (Remember? Switch to polygon select mode first.) and select UVW Map in the list menu. The direction of the mapping can be left as is. We only have to adjust the size and position of the texture.


In the list menu we select Unwrap UVW and open the editor. There, we use the scale and move tool to adjust the shape. The Scale tool also contains tools to scale horizontally or vertically only.

The image can be panned or zoomed with the view control at the lower right edge of the editor. The result should look like this:


We close the editor and collapse the editor stack. Then we switch to Polygon mode and click the Unhide All button. The tread becomes visible again.


We deselect the polygone mode by clicking on the polygone symbol and rename the cylinder01 to Wheels1.

The first wheel is done!


Making a wheelset from a wheel

To copy the wheel, we select it and also select the Move tool. Then, with pressed shift key, we leftklick (Not rightclick as stated before. Thanks to Ashley Ow for hinting me) onto the wheel. The copy dialog appears. Here we select Object Copy and click OK.


Now we have two wheels, Wheels1 and Wheels02.

Wheels02 is selected automatically. We select Selection Vertex in edit mode and select all vertices of the wheel Wheels02.


We rightclick onto the Move symbol which activates the Move-Type-In dialog box and change the X-value from 0.8 to -0.8. The whole wheel has moved.


One click on the Zoom Extents All symbol or Ctrl-Shift-Z and both wheels are visible in the viewports.


We deselect the Vertex Mode and select the other wheel (Wheel1). When more objects are visible, we can select objects with the Select dialog. To do so, we activate the Select symbol and press the H button. Here we mark Wheels1 and click Select.


In the modifying tool, we click on the Attach List button to be found below the Edit Geometry section


Here we select Wheels02 and click Attach.


The first wheelset is done.


Now we copy the whole wheelset by first selecting the Move mode and then Shift-Click on the object. In the dialog box which appears, we choose the option Object Copy and Number of Copies 2 and hit OK.


With the H key and the select dialog, we select Wheels02 and move it with the Move tool and Transform-Type_In to a Y value of zero meter.

Then we rename Wheels01 to Wheels2.


We do the same procedure to the Wheels03 object:

  • select Wheels03 with the H dialog
  • move with Move Transform-Type-In to Y -2 meter (minus 2.0 meter)
  • rename object from Wheels03 to Wheels3

Unhide the chassis

In the Display toolbox, we unhide the chassis by clicking the Unhide All button. Zoom Extents all gives us the right view.

Chassis and wheelsets are now ready.

Don't forget to save the file as gtd1_03.gmax.


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to part 4