3. Simple Construction - A Diesel Loco - Part Four

Version 2.0 - May 2008

Frame and body

Now you create the frame of the loco. To build the frame, you switch to the Top viewport first. From the Create menu, you choose the Standard Primitive Box. As you did with the wheels, you use Keyboard Entry with these values:

X 0 m (virtual world's center)
Y 0 m (virtual world's center)
Z 1.5 m
Length 9 m
Width 3m
Height 0.1 m
Check that all other values match the illustration. Change any that do not.
You also select Generate Mapping Coordinates.

NOTE: You select the Top Viewport because when you create a new shape on top of the existing shapes, which is what you want. Try selecting another viewport and create the shape and you will see that it does not show in the right place. This will give you an idea of why new shapes are created in different viewports.

One click on Create and here is the frame.

Zoom Extents All to fit the views to the screen.

The frame gets a texture

As you did with the other objects, you convert the frame to an editable mesh first. That's done with a right-click onto the frame. In the Quad menu you select Convert to - Editable Mesh.

Let's take this time to rename the new box to Frame01.

Use the Material Navigator. to apply the texture to the mesh.

The top plane of the frame shall get the grid texture while the side planes and the bottom plane should get the dark grey texture. Select the Front Viewport.

Select the frame in the front Viewport. Using the Modify Tool you use the Polygon Mode

Select all polygons of the sides and bottom of the frame (BE sure that Frame01 is selected). Start your selection from approximately the middle of the frame side down past the bottom of the frame.

Then you use the Unwrap UVW modifier (in the modifier list) and in the editor you map the frame to the small grey square at the bottom left if the image.

You close the editor and Collapse All on the Modifier stack.

The sides and bottom are now mapped with a solid gray color. Only the top polygons are not mapped yet.

Mapping the grid

With the frame selected in the Front Viewport, you select the polygons of the sides and bottom of frame the same way you did when you mapped the image on those polygons.

With a click on the Hide button, only the top polygons are left visible. You switch to the Top Viewport. Select all the polygons of the top of the frame and use the modifier Unwrap UVW and open the editor.

you see the image that you want to map for the grid flooring on the frame is rotated 90 degrees from the shape you want to map it to. The mapping vertices must be rotated by 90 degrees to get the image properly mapped to the shape. You will use the angle snap tool. This will snap the rotation in 5 degree increments, making this easier.

Select all the vertices and rotate them 90 degrees. Direction does not matter. Clockwise or counter clockwise. Then you shrink and position the vertices to the grid, as shown below close the editor and collapse the modifier stack.

Changing to Polygon select mode again, you click Unhide All and unselect Polygon select mode. Then you rename the frame to Main. .

You are finished with the frame. Save your project and continue on to make the body.

The body

You select the Top Viewport again (you are adding the new shape on top of the existing shapes)

You create the body like you created the frame, except that the body is divided into five segments. The values to be typed in are:

X 0 m
Y 0 m
Z 1.6 m
Length 8 m
Width 2m
Height 1.9 m
Length Seg 5 (number of length segments)

The checkbox Generate Mapping Coords must be checked.

The procedures for creating a shape should be familiar to you at this point. I will not detail each entry as has been done when you created the other shapes. Other procedures that have been repeated to this point will also be presented with instructions only.

Your results should appear like this.

In the side view, you see the 5 line seg sections.

Like the other parts, the body has to be Converted to Editable Mesh and given the texture using the Material Navigator.

Your results should appear the same as the image below.

Let's rename our shape from Box01 to Body now to avoid any confusion as you go along.

Body shaping

Now in the Left viewport, you use Modify and click on Vertex symbol in the Selection area. Then you select the upper outer vertices as shown in the image below. Selected vertices are shown in red. Hold the Ctrl key down to select both upper - side vertices. Selected vertices are red.

With the Move tool and the Move Transform-Type-In dialog you change the Z value to 3 meter.

Reminder: You do not need to close the Move Transform-Type-In dialog.

Then you select the vertices which defines the segments for the 2nd thru the 5th segment (separately) and type in the values as shown in the illustration.

Select the top and bottom vertices pairs in a reverse sequence, from right to left and enter the Y value into the Move Transform-Type-In dialog. Doing this in reverse sequence will keep the moved vertices from shifting too close to the others, which can make the selection process more difficult. Try it using a normal (Youstern World) sequence of left to right and you will understand.

When you are done you can close the Move Transform-Type-In dialog.

The resulting shape:

Detaching the center part to make the cabin

To use the center segment for the cabin, you will detach it. You change our selection mode to Polygon and select the center segment polygons by drawing a box like shown below:

In the Edit Geometry section, you click Detach...

Assign the name Cabin and leave the polygon select mode. The names Main and Wheels1 to 3 must not be changed or MSTS will cause errors)

The following section, to the end shows you the Array Tool as a method of creating, shaping and mapping the Roof to the Cabin.

This method results in lower poly counts in the finished mode than the Tessellate method that is shown in the Appendix Section 4.

I suggest that you save your project at this point, continue to the end of the entire project and then come back to this point and go through the alternate method outlined in the Appendix.

New polys for the cabin

Select the Cabin in the Side Viewport. In the Display toolbox you click Hide Unselected. All parts except the cabin will be hidden.

Use the Zoom Extents All to enlarge the Viewports.

Using the Front Viewport, click on Vertex selection mode. Select the outer pair of vertices on either side and using the Move Transform-Type-In dialog, you set the X parameters to 1.25m for one side and -1.25m for the other. This will stretch the cabin outwards from center. Then select the top pair of vertices and change their Z position to 4.5m to raise the cabin height. Zoom extents to center each viewport.

Now change to the Polygon select mode. Rotate the view in the Perspective Viewport to give access to the top of the Cabin. Select the 2 polygons that make up the top of the cabin and click on Detach. Name the new detached part Roof.

You are going to shape the roof using an array of 4 equal, identical sections of the roof. It may be easier to work only with the newly detached Roof. Activate Polygon select mode. The Roof polygons should still be selected. In the Display mode, Hide Unselected and you should only be left with the Roof showing

Moving back to the Modify mode, click on Vertex select mode. In the Top Viewport, select the vertices on the right and using the Move Transform-Type-In dialog, move these vertices to X -.625m.

De-select Vertex selection mode and go into the Hierarchy mode. Affect Pivot Only, then Center to Object and Align to World to set the pivot point as shown below. Close Affect Pivot Only.

Now you will open the Array Tool.

You want to end up with 4 copies of you shape, all lined up to the right of the existing shape on the X axis. This dialog box is cluttered and confusing when you first look at it. To get a full explanation of everything that is shown, look in the GMAX HELP under Array Dialog,

In the image below, the sections that you are concerned with are highlighted. Each section of the roof is .625m wide (in the X axis). Our existing shape is sitting on the negative side of the 0 line of the X axis, so you want our copies placed in a positive direction towards the 0 or centerline of the axis. You see the value 0.625m in the X Incremental settings. If our existing shape you sitting on the positive side of the X axis, you would want our copies placed in a negative direction towards the centerline and the value in the X Incremental box would read -0.625m.

You have Copy checked and the 1D Count set to 4. This will give us a total of 4 shapes identical to the first.

The Totals area shows that the resulting sum of the 4 shapes will extend for 2.5m along the X axis.

Enter your X Incremental value and the 1D Count value. The rest of the values are added by the tool.

Click OK.

You will see the 4 aligned sections appear in the Top and the Perspective Viewports.

Now, select the first panel titled Roof. In the Modify mode, use Attach List to join all the sections together into one shape called Roof.

You now re-attach the Roof to the Cabin. Select Display mode and click on Unhide by Name and select the Cabin and unhide.

Go back to the Modify mode and select the Cabin. Use the Attach List and attach the Roof to the Cabin.

Now you can manipulate and shape the roof section of the Cabin. Add a FFD 4x4x4 modifier to the stack. This is a Free Form Deformation modifier. The 4x4x4 defines a 4x4x4 matrix of control points to manipulate the shape.

Expand the modifier using the + next to it and select Control Points.

For this operation, I find it easiest to start with the Front Viewport.

HINT !! You can maximize the active Viewport by using the Min/Max toggle. This is located in the extreme lower right hand part of the GMAX interface.

It is hard to get a capture of the actual symbol.

I am using this the following illustration.

Zoom and position the Roof for a better view. Using the Move tool, and restricting movement to the Y axis, select the center sets of Control Points on the top, or roof section of the Cabin. The selected Control Points change color from orange to yellow. Move these up to achieve a curvature to the Roof.

This is not a precision move, since you have no dimensional data available. Don't extend this too high, or you will have difficulty when you texture the front of the Cabin.

Switching back to view all 4 Viewports, using the Min/Max Toggle; you see the roof section is now curved.

You can now collapse the stack and the you will add the front and back sides to the Cabin.

With the Cabin selected, in the Modify mode, you use Polygon select. Use the Perspective Viewport. Rotate and Zoom to show the Cabin in approximately the same position as shown in the illustration below.
Click on Create in the Edit Geometry rollup. You will see what appear to be vertices appear. You will use these vertices as the points to outline the new surfaces for the Cabin's front and rear.

Caution!

It is essential to create the polygons in a counterclockwise direction. Otherwise the Normals would face to the other direction and the polygon would not be visible from the outside.

Reference :

Normals are used to define which side of a face or vertex is considered the "out" side. The out side of a face or vertex is the side that's visible in viewports.

When you move the mouse pointer into the Perspective Viewport, you see a thin cross hair cursor.

As you move over a vertex, the cursor shape will change to a small cross. This will aid in selecting any vertices that are not visible in the viewport.

2 of the vertices do not show. There are 2 on the bottom part of the side, one in each corner. The illustration above shows one in the lower left corner. There is another on in the lower right corner. The cursor in the picture is a small cross. When the cursor is moved off one of the vertices, it will change to a cross-hair cursor. The 5 alignment points on the roof section are very difficult to locate if the shape is not oriented as shown in the illustration.

Start with any vertex you want, but be sure to work in a counter clockwise direction. Click on the first vertex and move to the next and click again, when your cursor changes.

Click once on each of the vertices in a counter clockwise sequence. A thin dotted line follows your cursor's movement. When you are over the last vertex, double click to complete the creation of the new face.

This is the result:

Rotate the shape in the Perspective Viewport to show in the same manner as the first side. You wont see the shape you just added, because the normals for that side are facing the other way.

Follow the same procedures as you did for the Front (working counter clockwise) and you will see the other side of the Cabin added.

Now if you rotate the shape in the Perspective Viewport, you will see that you have all 4 sides on the Cabin.

You are now ready to stretch the roof over the sides of the Cabin. You should still be in the Polygon select mode.
In the Top Viewport, select the 8 polygons of the Roof. (the cursor in the illustration below point to the area that shows the number of selected faces, or polygons) Now, click on Detach and name the new object Roof.

Stretching the roof

To insure that you do not stretch the Roof beyond the edge of the frame (Main), you will unhide all the hidden parts of out loco. In the Display mode, click on Unhide All. You now see all the parts you have made up to this point. You should not have to Zoom Extents. You will be using the Top Viewport to stretch the Roof.

Go back to the Modify mode and de-select the Polygon selection mode and select the newly detached roof using the Select List on the Tools menu. In the the Modify panel, click Vertex select

Our goal is to both stretch the length of the roof and to widen the roof over the edges of the cabin. Select the Top Viewport. Click on the XY-Axis in the toolbar. This will restrict movements to the X-axis and Y-axis only. Select all the roof's vertices and stretch them with the Non Uniform Scale tool. This is another "eye-ball" move, with no specific dimensions. I used the edges of the Frame as my guide. As you move this you will see the changes in all the Viewports.

Still in the Vertex select mode, you can use the Move tool and the Move Transform Type-in to select and move the front and back vertices to a position that you feel looks right. Zoom all Extents and your model should look something like this:

The faces of the roof are only visible from above due to the direction of their normals. To make the under side visible (when you are inside the cab), you have to copy the roof and flip its normals. To do so, you deactivate the vertex selection mode and with the Move tool activated, you Shift-Click on the roof to make a copy.

Then you switch to Polygon selection mode (the new object Roof01 is selected automatically) Select all the Roof01 polygons. As another aid, you can check the box next to Show Normals in the Modify Rollup. This will show you the directions of the existing Normals.

Scroll the Modify rollout down until you see the Surface Properties section. In the Normals section you click the Flip button.

You can see the direction of the Normals for Roof01 have changed and it can now be seen from below.

You deactivate the polygon selection mode and select the primary roof object Roof Select List . Then you attach the object Roof01 with the roof using Attach List.

With the selected roof you change to the polygon select mode and select all the polygons of the Roof. You should show 16 faces selected. You add the UVW Mapping modifier to the stack. This should the Alignment set to Z. Then you add the Unwrap UVW modifier to the stack and select Edit.

With all the vertices selected in the editor, you resize and move the mapping vertices to the roof section of the image. OK, you can't get the mapping vertices to line up correctly using the tools you know. You will use a new tool to get the alignment you want.

This is the Horizontal Scaling Tool in the UVW mapping editor. It will stretch or contract the selected mapping vertices along the horizontal axis only. The other tool not used here, but shown in the illustration is the Vertical Scaling Tool that does the same thing on the vertical axis.

Using the Scaling Tools and the Move Tool, align the mapping vertices as shown below. Zoom and move the image to get the placement of the mapping vertices as accurate as possible.

You can now close the editor and collapse the stack. You are finished with the roof.

We can now join the Roof, Cabin and Body into a single shape.

Use Select by Name

to select the Cabin. In the Modify rollup, use Attach List to attach the Roof to the Cabin.

Select the Body and attach the Cabin to the Body.

Save your project and you will continue on to map the Body.

Mapping the body

First, you map the front and rear of both body and cabin. Select the Body. In the Modify rollout change to Polygon mode. You select all the polygons on the front of the cabin first. Press the CTRL-key. Hold it down and select the polygons on the front as shown in the illustration below.

In the Modifier List select UVW Mapping and add it to the stack. In the Alignment section, check Y and click on Fit.

This should be the result:

WARNING !!

If you intend to have your model reskinned by others, see the Warning about moving or resizing mapping coordinates in the Appendix Section 5.

In the Modifier List select Unwrap UVW and add it to the stack. Open the editor and select all mapping vertices. Resize the mapping grid and position it over the cab/grill area of the image. Zoom and move the image to give yourself a larger view to work with. See the illustration below:

Then you close the editor and collapse the stack. This is the result:

You should still be in the polygon select mode, with the mapped polygons selected. If not, reselect them. Now you Hide the already mapped polygons to prevent them from being re-selected and remapped.

Using the Side Viewport you draw a box to select all the polygons for the sides of the Body. Now, you select all side-facing polygons.

Add the UVW Mapping modifier to the stack. In the Alignment section check X and click on Fit.

Now you add the Unwrap UVW modifier to the stack and open the editor. The grid of mapping vertices need to be rotated 90 degrees counter clockwise. Select all mapping vertices and rotate the grid.

Using different combinations of resizing and moves, you want to get the grid aligned to the image as shown below.
You can see that this image does not truly conform to the shape. Moving individual or multiple mapping coordinates will skew the mapped image on the shape. The horizontal lines along the Cabin section are lower than those on the front and rear parts of the body. In this particular case, if the mapping coordinates were moved equally in all axis, the Cabin windows would not be completely visible. The changes you make in the mapping editor are immediately visible in the Viewports.

You close the editor, collapse the stack and here is the result.

You still have all the side polygons selected. Click on Hide.

Now it's time to get rid of the bottom polygons of the body. You can't see them, but MSTS has to calculate them. You select the bottom faces as shown and delete them with the Del key. You see the vertices arrows disappear from the screen.

Now, you select the upper faces of the body.

You add the Unwrap UVW modifiers to the stack. In the editor, you resize and move the mapping vertices to a solid blue section of the image as shown below.

After leaving the editor and collapsing the stack, you click Unhide All in the polygon selection mode and the body is done. Don't forget to save the work.

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to part 5