Creating Terrain

To finish the exercise, you'll place the outpost at a crossroads in a hilly countryside. To make the terrain, you'll apply a Noise modifier to a Plane object. Among other things, this section will show you how to apply a modifier to part of an object.

Start the terrain

1. Start from the previous section, or load the file you saved from there, or load the file outpost03.gmax.

2. In the Top viewport, zoom out quite far, so the outpost is about half an inch in diameter.

   

   Tip: An easy way to zoom out in an active viewport with a wheel mouse is to position the mouse cursor at the center, and then roll the wheel towards you. And to zoom in, roll the wheel in the opposite direction.

3. On the Create panel > Object Type rollout, click the Plane button.

4. Dragging from corner to corner, add a plane that fills most of the Top viewport.

   The plane is automatically created on the construction plane, which, in the Top viewport, is the XY plane at Z=0. Thus, it sits at the exact same height as the bottom of the outpost structure.

5. In the Parameters rollout, set Length Segs and Width Segs=40.

   

   As with Twist, the extra resolution is needed to give the modifier additional geometry to work with.

   In the next several steps, you'll select part of the geometry, apply a modifier to it, and then transform the geometry. To do this, you could convert the plane to an editable mesh or poly (polygon) object, but then you wouldn't be able to go back and change the resolution, if necessary. Instead, you'll use a modifier that lets you select part of the geometry and pass it up the stack to a another modifier. It also lets you edit the mesh as if you had converted it.

Edit the mesh

1. In the Top viewport, right-click to exit Create mode.

   The plane is still selected.

2. Go to the Modifier panel, and from the Modifier List > Mesh Editing category, choose Edit Mesh.

   The Edit and Select modifiers and other tools in gmax provide access to a range of geometry sub-object levels, including vertex, edge, and element. This feature gives you as much control as you need over the level of detail at which you edit an object.

3. In the modifier stack display, expand the Edit Mesh hierarchy and click Polygon (you might have to scroll down to see it).

   The Polygon button at the top of the Parameters rollout is highlighted. You can also use this button to access the polygon sub-object level.

   Next, you'll select a column of polys in the plane object.

4. In the Top viewport, position the mouse at the top of the plane object, about four or five columns left of center. Press and hold the mouse button, and then drag down and to the right, until you've selected a vertical path consisting of about 10 columns of polys.

   

5. Position the mouse at the side of the plane object, about four or five columns above the center. Press and hold the CTRL key, and then the mouse button, and drag down and to the right, until you've selected a horizontal path consisting of about 10 rows of polys.

   Because you're using the CTRL key, the new selection is added to the existing one.

   

   You've just selected the polys that shouldn't be affected by the Noise modifier. These will become the road area, which you want to be flat. You'll remedy this by inverting the selection.

6. From the Edit menu, choose Select Invert.

   The previously unselected polys are now selected, and vice-versa.

   

Apply the Noise modifier

You're now ready to apply the modifier.

1. From the Modifier List > Parametric Modifiers category, choose Noise.

   The Noise modifier applies random displacement to the selected parts of the plane, simulating a hilly or bumpy surface. No change is apparent yet, because you still need to set up the modifier. Because you want the polys to be displaced vertically, you'll apply the noise on the Z axis.

2. On the Parameters rollout > Strength group, set Z=500.

   

   The Noise modifier distorts only the polygons selected in the Edit modifier. This is the gmax modifier stack at work; selected sub-objects are passed up the stack to be modified without affecting the entire object.

   The hills are unnaturally pointy. You can correct this with the Scale setting, which determines how spread out the noise variations are.

3. In the Noise group, click and hold on the Scale spinner control, and drag upward slowly. Stop at 500 or so.

   As you drag, the noise patterns expand outward from the center of the plane (actually, of the modifier) until they're much smoother.

   

4. Try changing the Seed value.

   This setting lets you change the randomization of the noise, so that you can vary its effect among different objects if necessary.

Adjust the road height

There's one more adjustment to make. In the real world, roads of this sort are usually dug out of the surrounding hills, so they're lower than the hills. You can simulate this by moving the selected polys.

1. In the modifier stack display, click the Edit Mesh item.

   The Polygon level is still active. But the plane has suddenly gone flat; you can't see the noise effect any more. That's because, when you move down the stack, by default gmax usually doesn't show the effects of higher modifiers, for simplicity's sake. You can, however, still see them if you want.

2. In the row of buttons immediately below the modifier stack display, click the Show End Result On/Off Toggle.

   The hills reappear. The grid you see is the "before" state, showing the plane prior to being affected by the modifier.

   Because the "hills" part is selected, you'll move this upward, rather than moving the road areas downward. This also obviates moving the outpost to stay on the roadway.

3. Right-click in the Perspective viewport to activate it without changing the selection. If you inadvertently left-click and lose the selection, get it back with Undo.

4. Click the Select And Move button, and drag any of the Z axes of the Transform gizmos upward until the hills rise significantly above the road level.

   

   Lastly, you'll unfreeze the original parts of the outpost structure.

5. In the modifier stack display, click the Noise item to exit the sub-object level of the Edit Mesh modifier.

6. Right-click in the active viewport, and from the quad menu > Display quadrant, click Unfreeze All.

   The floors and rings can once again be manipulated, but they're still transparent.

7. Select all objects, and in the Display panel > Display Properties rollout, click the See-Through check box twice.

   The first click makes all objects transparent, and the second returns them to their original colors.

   

   The final outpost level

8. Save the scene as my_outpost04.gmax.

   You can compare your results with ours in the file outpost04.gmax.