3. Simple Construction - A Diesel Loco - Part Five

Version 2.0 - May 2008

The bumper supports

You create the bumper supports with a Create - Box - Keyboard Entry in the Perspective Vewport. The values are:

X = 0.0m
Y = 4.5m (Our Chassis is 9.0m long)
Z = 1.1m
Length = 0.4m
Width = 3.0m
Height = 0.4m
Generate Mapping Coordinate must be selected.

A click on the Create button creates the front bumper support.

Convert this to an Editable Mesh.

Texturing the bumper support

You open the Material Manager, select our texture and apply the texture to the bumper support.

Select the Modify Tool and map the bumper support planes by adding the Unwrap UVW modifier to the stack and in the edit window set the mapping vertices into the small dark grey square of the image.

You close the editor, collapse the stack and the front bumper support is done.

You select the bumper support, and with Move activated, you Shift-click on the bumper support to copy (or clone) it. In the dialog box, you click OK. The copied bumper support (Box02) is now selected and can now be moved using the Move Transform-Type-In dialog (opened with a right-click on the Move symbol) you change the Y-value from 4.5m to -4.5m. The support has been moved and you can now close the Move Transform-Type-In dialog.

Next, you select the Main (frame) object and with the Attach list tool, You select both the bumper supports (Box01 and Box02). They are now attached to the Main object.

The bumpers

To construct the bumpers, you first change the Front viewport to Back viewport. In the Customize menu (top of screen), select Viewport Configuration. Click on the Layout tab, then click the Front Viewport and change it to Back.

In the Back viewport, you create a cylinder with the keyboard entry method. These are the values:

X: -0.9m
Y: 1.3m
Z: 4.8m
Radius 0.2m
Height 0.5m
Height Segments: 5
Cab Segments: 1
Sides: 18
Generate Mapping Coordinates must be selected

This is what the bumper should looks like:

You leave the cylinder selected and convert it to an editable mesh. Then, you change to the Left Viewport and zoom in with the

Region Zoom tool.

Draw a box around the area you want to Zoom in on.

Use the Min/Max Toggle to focus on this Viewport

You switch to the Vertex mode and select the two right-hand rows of vertices...

...then you activate the Select and non Uniform Scale tool and open the Scale Transform Type-In window with a Right-click on the Select and non Uniform Scale symbol.

In the Scale Transform Type-In window, you type in the Offset : Screen fields the following values:

X: leave unchanged
Y: 60
Z: 60

Caution! The values will revert to 100% in the entry fields after you enter your values. You will see the mesh change with each entry.

Don't close anything and then select the two center rows of vertices...

...and in the Scale Transform Type-In dialog, you type in the following values:

X: leave unaltered
Y: 40
Z: 40

You are finished using the Select and non Uniform Scale tool and can close the Scale Transform Type-In window.

Using the Move tool and the Transform Type-In dialog, you adjust the rows with the following Y-values:

1. Y: 5.35m
2. Y: 5.3m
3. Y: 5.25m
4. Y: 5.0m
5. Y: 4.9m
6. Y: 4.7m

As shown in the illustration below.

The resulting shape should appear like this:

You can close the Transform Type-In dialog and de-select the Vertex mode. Using the Material Navigator, you apply the material to the mesh the same way you have done before.

...and map the bumper sides on the small grey square. (Remember? Unwrap UVW and to finish Collapse All)

Then, you switch to Polygon select mode and select the side facing polygons.

Hide the selected polygons. The Front faces of the bumpers are still visible and due to be mapped next.

If you used the Min/Max Toggle, you will want to switch back to see all 4 Viewports.

I you are not still in the Polygon select mode, activate it. Select the front polygons in either the Perspective or the Back Viewports Add the UVW Map (with the Z axis Alignment checked) and then the Unwrap UVW modifiers to the stack. Map the bumper's front faces to the small dark circle as shown

Collapse the stack and return to Polygon mode. Then, Unhide All. De-select the Polygon mode.

To copy the bumper

Make one copy of the bumper. With the Move tool Shift-Click on the bumper and make one copy. Move the copied bumper (cylinder02) from X: 0.9 to X: -0.9.

Select the first bumper(Cylinder01). With Attach List, you attach the second bumper (Cylinder02) to the first bumper.

Now, you make a copy of the new bumpers. In the Side Viewport use the Rotate tool to rotate the copied bumper 180 degrees... (With the Angle Snap Tool activated).

...and move it to the rear side of the loco. Therefore, you change the Y-value in the Transform Type-In dialog from 4.8m to -4.8m.

NOTE: At this point in the tutorial, you have been presented with many useful tools to aid you in creating things in GMAX. Zooming, rotating views, assigning different views to Viewports, etc.

You have also seen in the different GMAX screens things that I have not used, that you may find useful. Setting up your screen to display a single viewport will give you a large image to work with, as an example.

I will follow the format of the original tutorial through this part with very little hand-holding details presented on how to do common operations. So, with that known, let's forge on...

Building the connecting rods will use FREEFORM MODELLING.

NOTE: The original information presented for this section contained very little dimensional data for the connecting rods. Most of the size and shaping are done by eye and I will leave the method originally presented intact, though reworded where necessary.
Being able to make parts for a project using this method will make it possible to be create parts from photographs and other sources that show no dimensions. In other words FREEFORM MODELLING.

Of course, if you have detailed plans for your project this becomes mute.

The connecting rod

To build the connecting rod, in the Top Viewport you will create a box with the following dimensions:

X: -2.0m
Y: 0.0m
Z: 0.0m
Length 6.0m
Width 0.5m
Height 0.5m
Length Segments: 11
Width Segments: 1
Height Segments: 1
Generate Mapping Coordinates must be selected

Convert it into an editable mesh and map it completely to the red square. (with the Material Navigator and Unwrap UVW and the editor).

Using the tools you have available, you want to see something like this in the side view.

I have made the Side Viewport the only one visible on my screen. I have also Zoomed in on the area of the Drivers and the Connecting Rod. I've used one tool that has not been used before in this tutorial, the Select and Uniform Scale tool.

I moved the box and used vertex selection to move the lower set of vertices up to get a rectangular shape of the segments using the Move Transform Type-In.

Rename Box01 to Rod01

Specific dimension and positioning data is not available for this**, everything is done Freeform, to look right.

Now, you select the vertices of the rows1,4,5,8,9 and 12 with the CTRL key pressed. With motion restricted to the Y-axis you taper the rod with the non uniform Scale tool as shown.

Then, with movement restricted to the X-axis you align the vertex rows with the Move tool.

Rather than doing this entire operation by eye, you can create the first connecting point visually by focusing you your view to the left side of the rod, and the 1st 4 vertices.. Shape an approximate rod connection point by moving the vertex pairs. This doesn't need to be perfect, just a rough approximation. Using the Move Transform Type-In, set the distance between the 1st and 2nd setss of vertices and the 3rd and 4th sets of vertices to the same value. Set the distance between the 2nd and 3rd sets of vertices to a larger value. On my model, I found that a difference of .01m gave the best results.

HINT !!

Write down the Y values for each pair when you have the distances set. This will be used to set the remaining vertices positions. Set up a matrix to calculate the values that you will use for the other 8 pairs of vertices to create symmetrical, equally spaced connecting points.

	Vertex Pair	1st Connection	Vertex Pair	2nd Connection	Vertex Pair	3rd Connection
Y Position	1	x.xxxm	5	x.xxxm	9	x.xxxm
Y Position	2	x.xxxm	6	x.xxxm	10	x.xxxm
Y Position	3	x.xxxm	7	x.xxxm	11	x.xxxm
Y Position	4	x.xxxm	8	x.xxxm	12	x.xxxm

Our wheels are positioned at 2.0m intervals. Using the initial Y position values you record for the 1st Connection point, you calculate and record the values for the other Connection points. Subtract 2.0m from the 1st Connection point to get the value for the 2nd connection point and then subtract 2.0m from the 2nd Connection point to get the value for the 3rd.

As an example:

Vertex Pair 1st Connection Vertex Pair 2nd Connection Vertex Pair 3rd Connection

Y Position 1 1.99m 5 -.01m 9 -2.01m

The values for A and B that I used can be found in the Appendix, Section 3.

Now you have the first connection point done. Using the Y values that you wrote down when you created the 1st connection point, you can use the Move Transform Type-In dialog box the set the positions of the remaining connection points using the matrix you calculated. I recommend working in reverse order, from the right to the left so that selection the vertex pairs is not so difficult.

Your connecting rod should look something like this:

This doesn't look too bad, but it is not centered to the drivers. Click anywhere in the viewport to deselect any selected vertices. Then click Vertex selection to turn it off. Enlarging your screen to show the center wheel's center point and the Connecting Rod's connection point, you can move the Connecting Rod to the approximate center of the wheel. Restrict movement to the X axis.

In the Back viewport, you adjust the rod width. Then restricting movement to the X-axis move it to the wheel.

With the Hierarchy tool you select Pivot and Affect Pivot only. Then you click Center to Object.

Then you make a copy of the rod and move the copy to the other side of the loco (In the Move Transform Type-In dialog change the X value from - to +). With the Attach list you attach the copied rod to the first rod.

The model is now ready and has yet to be animated and exported.

Don't forget to save the model.

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to part 6