Creating an outdoor area with Gensurf

Original tutorial provided by Ricebug, written with QERadiant in mind.

This tutorial will involve making an outside area and sky box. For making realistic-looking landscape, we will also be using the stand-alone version of David Hyde’s fantastic terrain generator program, GenSurf. A plugin version is available for QERadiant also.

Making the Ground with GenSurf

Since David Hyde keeps improving GenSurf, the instructions below may not follow the current update.

Figure 1: GenSurf's interface (click for larger image)

3. We’re going to use a grayscale bitmap to form our ground elevations. If you want, you can left-click on the one in Figure 2 and save it as a .BMP to a directory of your choosing. Click on GenSurf’s Bitmap tab and browse to this location.

4. Compare the bitmap below with the wireframe preview in Figure 1 above. The black areas dictate the lower elevation, while the whiter areas cause the ground to swell upward. Lightwave and 3DSMax users know this as "displacement mapping." For example, by drawing thick, black lines on a white background, you can easily define drainage ditches or culverts. In reverse, drawing thick, white lines on a black background will give you walls. Shades of gray in between black & white will cause variations in the height of your walls. Some interesting landscapes can be created with a little imagination.

5. Now click on the Extents tab. Under Lower-Left Corner, type –128 in both boxes. Under Upper-Right Corner, type 128 in both boxes. This will give an area size of 512 pixels, the exact dimensions of our bitmap. Also set Number of Divisions to 16 in both boxes. This will make for a smooth ground.

6. Notice that your map preview shows a steep terrain. We want our ground to flow downward in a smooth angle. To achieve this, change Map color 0 to 50, and Map color 255 to 100. Press Tab on the keyboard and your map should smooth out.

7. Click on the General tab and set Roughness to 0 and Random Seed to 1.

Adding the Ground to the Map

2. With nothing in the editor, click on FILE and choose OPEN (Not LOAD). Select the map of the rooms and hallway we’ve been working on. (Hopefully, you’ve been saving things.)

3. Now click on FILE. This time, choose LOAD and select the GenSurf terrain you made. You should have both the terrain (in red) and the other map file, as shown in the screen shot below. Leave the terrain selected.

4. With the terrain in red, click somewhere in its center and drag it towards the bottom of your screen (you should be looking at the XY Top view). Drag it so it rests on the outside wall of the square room as shown in Figure 3.

Figure 3: Ground object in place

5. Since I want the ground to slope down, away from the building, we’ll need to rotate it.  Look at the row of 6 buttons circled in yellow in Fig. 4. These show the different rotation commands for X, Y, & Z. With the ground still selected, you want to click on the last (ZN) button TWICE, or you can click the Y|Y button ONCE. The difference between these two buttons is that ZN rotates a selection clockwise at 90-degree increments, while YY vertically flips the selection. The end result is the same.

Y|Y flips brushes vertically on the screen; X|X flips them horizontally.

Figure 4: Ground lowered to same elevation as floor

8. The next thing we want to put in are some walls to enclose the ground. It would look unrealistic to bring the sky texture down to the ground. I added a "stepped" down stone fence along the sides.

9. Next, select the sky texture and build a box to enclose the fence and ground. The "walls" of the sky box should rest flush against the outside of the fence. The "ceiling" of the sky should come just above the "roof" of the exterior building. See figure 5.

Figure 5: Constructing the Sky Box (click for larger image)

After you finish the skybox, let’s make a small pool of water in the lower depression to give our yard some character.

Figure 6: Adding water (click for larger image)

The completed outside area.

Copyright 1999, by Terry DeLaney. Permission is granted to distribute this file as long as the author receives credit.