Create and Apply Terrain Texture Maps

To paint the terrain, follow the steps below:

1 Open WorldEditor.

2 Click the Terrain Texture Tool toolbar button () or use the shortcut key 2 .

3 Select the Asset Browser panel.

4 Select the Textures virtual folder.

5 In the file list, double click the desired texture – it will be automatically displayed in the Terrain Texturing panel's Active Texture group box.
You can also drag the texture onto the active texture slot from the Asset Browser.

 

6 Adjust the brush settings before painting the terrain.

The Size field determines the diameter of the terrain paint brush. It can be changed by typing a new value, by moving the slider with the mouse, or via the [ (left square bracket) and ] (right square bracket) shortcuts (which decrease and increase the value, respectively).

The Strength field defines the "flow of ink" onto the terrain. A high setting will cause the terrain to quickly adopt the texture you are painting. The strength can also be changed by typing or by using the slider, but has a different keyboard shortcut: Shift+[ (left square bracket) and Shift+] (right square bracket) to decrease and increase the value, respectively.

The Opacity sets a maximum percentage at which the current texture will be applied to the terrain. This field can also be changed by typing or by using the slider.

7 Drag the mouse over the terrain to paint it with the active texture.

The Sample Texture feature (indicated by the icon) is activated by the Alt keyboard shortcut, and chooses the strongest texture under the cursor, making it the active one (automatically updating the Active Texture group box's panel).

Alternatively you can right click on the terrain whilst in terrain-painting mode, and choose Select Texture for Painting. This will give you access to all the textures underneath the cursor.

There is also an option to Select Texture and Opacity for Painting

Alternatively, you can right click the Chunk Textures panel to select a texture for painting.

Just as with masks in Photoshop, you can use a number of masks to select or deselect areas of the terrain you wish to paint. When using multiple masks they multiply together to mask out the terrain.

All masks can be previewed actively on the terrain whilst painting by ticking the Show Overlay tick box. The mask will be displayed as a red area (masked off). In the example below a height mask was used to enable editing between the heights 250m and 300m.

Masks can be saved as brushes to be used at a later date

Once saved they will appear in the Asset Browser under the Brushes filter folder

 

The available masks include:

Height: selects a minimum and maximum height for which terrain painting is allowed. (Fuz adds a blur around the borders of this selection.)

Slope: selects a minimum and maximum slope for which terrain painting is allowed. (Fuz adds a blur around the borders of this selection.)

Texture: selects a texture currently on the terrain to be used as a mask. This selection is handy for replacing one texture with another. You can also use the invert texture mask to invert the selection.

The Include Projection setting will exclusively mask areas with both the same texture and projection. Both of these settings can be chosen by right clicking on the terrain.

Alternatively, you can right click the Chunk Textures panel to select a texture for use as a mask.

Noise: generates a perlin noise used as a mask on the terrain. The button accesses a noise generation window which allows the user to alter the noise parameters.

 

Imported: allows the user to import a greyscale texture to be used as a mask over the terrain.

Third party tools like World Machine can create terrain texturing masks which, when used in combination with imported height masks give rapid and realistic results.

There are several example masks in fantasydemo\example_terrain_textures. The following section uses them to demonstrate the power of using imported height masks.

The button will bring up a top down view of the entire space and allow the user to adjust the position of the imported mask. The interface acts similarly to the terrain height map interface. Supported formats include .r16, *.raw, *.bmp, terragen *.ter, DTED2 *.dt2.

An entire space can be flooded by using the . Be warned, this can take a significantly long time to do for extremely large spaces and will sometimes have to flush the undo buffer (you will be warned by a confirm prompt in such situations).

Using imported masks to rapidly texture terrain

Firstly a new space is created with a default grass texture map.

A heightmap is imported, creating mountains in minutes.

A texture mask is imported which describes all the cliff face areas and a rock texture is placed in those areas.

A texture mask is imported which describes all the areas that have eroded and a dirt texture is placed in those areas. The height and slope mask settings are used to map the parts of the terrain where fallen snow would rest, and a snow texture is placed on the mountains.

This whole process took only minutes. The masks were generated from World Machine in under an hour.

 

To edit .R16 files in photoshop ( photoshop CS2 & above will be required ):

- Choose File Menu - Open As

- Select .RAW format

- Follow the settings below, then click OK. Now you can edit the file in photoshop!

The BigWorld terrain engine allows the artist to paint an unlimited number of textures on the ground in any area. However, users should show some restraint – the more textures painted, the more memory used and the more draw calls performed. Therefore, it is crucial that all terrain texturing is done with an informed understanding of the texture management tools.

The first thing that must be understood is the concept of chunks. The terrain is divided into 100 x 100m segments called chunks.

Chunks can be visualised in WorldEditor by pressing the Chunk Visualisation toolbar buttons.

Each chunk can support an unlimited number of different textures and projections. However, the number of draw calls performed to draw the terrain is a function of the number of texture layers divided by four. So if you have 1,2,3, or 4 textures on a single chunk the graphics card will be able to draw that chunk in a single draw call, but as soon as you add one more texture, you are adding another draw call.

Number of textures per chunk	Number of draw calls
1,2,3,4	1
5,6,7,8	2
9, 10, 11, 12	3

It is therefore useful to browse around the space with the Chunk Texture panel open and the track cursor option selected.

When you come across a chunk that is using 5, 9, or 13 textures, removing a single texture from that chunk will decrease the number of draw calls by one.

To manage the number of textures per chunk, follow the steps below:

1 Open WorldEditor.

2 Click the Terrain Texture Tool toolbar button ().

3 Activate the Chunk Textures panel – on the viewport, right-click the terrain, and in the context menu, select the Manage Textures menu item.

The Chunk Textures panel can also be activated by selecting the View→Show Chunk Textures Panel menu item.

The texture management tool allows you to view those chunks that exceed a given number of textures (specified in the Maximum Textures Per Chunk Warning field.) If the button next to the field is pressed, then a red border will be placed around those chunks that contain more than the specified number of textures, and the text Too many textures will be printed on the problem chunks.

4 To reduce the number of textures in a chunk, right-click the texture that you wish to remove, and in the context menu, select the Remove Texture menu item.

 

You can also merge multiple textures. To do this, hold down the control key and consecutively select multiple textures from the Chunk Texture panel. The last texture you choose should be the texture and projection you want to merge to. In the case below, the grass (1) and leaf (2) texture will be collapsed to the dark rock texture (3). Note the harder red boundary around texture 3: this indicates the last selected texture. Now right click on the last selected texture and choose Merge Textures.

 

Alternatively, you can paint over the texture that you want removed with other existing textures – the automatic texture management system will remove a texture if its contribution to the chunk falls below a certain point. To do this, select the strongest texture under the cursor, using the Sample Texture feature (activated by the Alt keyboard shortcut and indicated by the icon). Paint over the problem texture until it is no longer visible. If you have sufficiently covered the problem texture, then it should automatically disappear from the Chunk Textures panel.

You can replace one texture with another by dragging a texture from the Asset Browser onto one of the textures in the Chunk Textures panel.

Another way of limiting the number of textures per chunk is to use the Automatic Layer Limit function.

With this option ON, the texture tools will never paint more than the specified number of textures per chunk. Once the chunk limit is reached, adding a new texture will automatically replace the least contributing texture in that chunk. This option defaults to a maximum of 4 textures per chunk when using BigWorld's simple terrain.

It is possible to project textures from any angle, just as you would a planar projection in 3dsMax or Maya. In the example below, the rock texture has been projected from two different angles: on the left it was projected from above, resulting in a stretched texture, whereas in the image on the right it was projected sideways onto the side of the hill, thus removing any texture stretching.

There are two ways to alter the projection of a terrain texture that has not yet been applied to the terrain.

Alter Terrain Texturing, Active Texture panel's projection Yaw, Pitch, Roll and UV fields.

Use the Alt + Shift + Left Click key combination to select a projection from the terrain normal.

If the texture whose projection you wish to alter is already applied to the terrain, you must use the edit projection button .

This will bring up a gizmo on the terrain which will allow you to alter the projection and scaling of the current texture. Alternatively, you can use the projection and scale sliders in the active texture panel.

 

Warning: Each newly projected angle creates a new texture layer. Too many terrain layers will impair the engine's performance. Try to limit the use of different projections to instances where it is really necessary.

The example chunk above is using the same grass.tga texture, projected at five different angles – the result is five texture layers being used. Each new texture layer is another draw call, which results in increased memory usage (due to the mask information).

 

In the example below, the same path.tga texture has been applied to the terrain with five different texture scales.

There are two ways to alter the terrain texture scale:

Alter Terrain Texturing panel's Active Texture group box's U and V fields.

Use the Terrain Projection gizmo (activated by the Shift keyboard shortcut).

Warning: Each newly resized texture adds another texture layer, even if the same texture is resized multiple times per chunk. Therefore, be careful when painting texture to only change texture scale when absolutely necessary.

The terrain exhibits specular lighting. The colour of this specular light is a combination of the terrain diffuse colour and the colour of the sunlight.

The contribution of each can be adjusted using the terrain watcher specular diffuse amount (see below).

The terrain texture has to be a .tga file – this is because the specular strength is determined by the alpha map, which cannot be specified in .bmp files.

White areas in the alpha map generate bright specular highlight, while black areas generate none.

The terrain texture in the example below has specular highlights on the smooth surfaces of the cracked mud, but none within the cracks.

Colour information

Alpha information

Specular lighting applied to texture

Adjusting terrain specular properties via watchers

Each object in BigWorld has a material kind. Material kinds can also be assigned to each terrain texture. This allows you to script different sounds, effects, etc depending on what terrain texture is being interacted with.

Terrain texture material kinds are defined in bigworld/res/system/data/material_kinds.xml

<kind>
		<id>	9	</id>
		<desc>	Snow	</desc>
		<sound> snow    </sound>
		<help> Hard crunchy snow. </help>
		<sfx>	sets/global/fx/sfx/sfx_pchang_snow.xml </sfx>
		<terrain> sets/t_ice/maps/terrain/ice_snow </terrain>
		<terrain> sets/t_ice/maps/terrain/ice_snow_pure </terrain>
		<terrain> sets/t_ice/maps/terrain/ice_snow_pure02 </terrain>
		<terrain> sets/t_ice/maps/terrain/snow_grass </terrain>
		<terrain> maps/landscape/ls2_snow01 </terrain>
		<terrain> maps/landscape/minspec_snow </terrain>
		<terrain> maps/landscape/minspec_mud </terrain>
</kind>

Clouds dynamically cast shadow on the terrain and outdoor objects. This is done automatically, and is calculated from the actual clouds in the world.

World shadowed by clouds