Grass Settings

Sets a number of grass clusters (or plants, or flowers) lined up horizontally in the diffuse texture. Read more about this parameter here.

Sets the size of the cells into which the grass field is split.

• The higher the step value, the bigger the cells the field is split into. But there exists a limit how many grass quads can be planted in each cell. So after reaching this limit, the number of grass quads can no longer be increased, though the Density parameter specifies it.
• The smaller the step is, the smaller the cells the field is split into. While the density value stays unchangeable (for each separate cell), the whole field becomes planted with grass more densely.

To learn more about the parameter, read the Step for Cell Division chapter of the Grass article.

Determines the mean value for the height of grass blades quads rendered in areas with the minimum density according to the image mask. The higher the Min height value, the higher the grass is in areas with the minimum density.

Min height = 1; Spread = 0.3 The grass height varies from 0.7 to 1.3

Min height = 1.2; Spread = 1 The grass height varies from 0.2 to 2.2

Determines the mean value for the height of grass blades quads rendered in areas with the maximum density according to the image mask. The higher the Max height value, the higher the grass is in areas with the maximum density.

Max height = 3; Spread = 0.3 The grass height varies from 2.7 to 3.3

Max height = 3; Spread = 1 The grass height varies from 2 to 4

Sets an aspect to calculate the width of a grass quad:

Aspect is set for each of the diffuse texture columns separately and can be randomly varied if the spread value is set in addition to mean one.

Sets an integer value used to generate pseudo-random successions of numbers. The parameter is used to randomly position grass blades quads across an area by an image mask.

To get a random seed value, press the Randomize button.

Mask that determines the density distribution of the grass.

• The mask is a 4-channel (RGBA8) texture:

  • Red channel specifies the areas of growth for the 1st texture column. If there are several grass clusters in a vertical column, they will be randomly spread across the masked area.
  • Green — for the 2nd texture column.
  • Blue — for the 3rd texture column.
  • Alpha — for the 4th texture column.
  Notice

  In case R8, RG8 or RGB8 texture is used as a mask, the diffuse texture must have only one, two, or three columns. So, if your diffuse texture contains, for example, only one vertical column, the R8 texture should be used.
• Zero channel values specify areas where the grass should not grow
• Non-zero channel values create a grassy area: the higher the value, the denser the grass grows.

Controls starting from what density (according to the mask), the grass should grow. This means, that if in some particular place the threshold value is higher than the color or alpha value of the mask, it is rendered grassless.

• With the minimum value of 0, the grass is planted on the whole area, that is specified as available by the mask.
• With higher threshold value, the grass will grow only in the areas marked by the mask as dense. The areas of sparse distribution stay bare.
• With the maximum value of 1, there will be no grass at all.

Flips an image mask vertically. For example:

Grass growing according to original Image Mask

Grass growing according to Image Mask flipped vertically

After flipping the image mask by the Y axis, the grass has started growing on the stony area. Density and color of grass growing on the presented area have also changed.

Mesh-based mask that is used to specify areas where grass can grow. A mesh for masking should be a simple planar mesh.

• If used together with a Field Spacer object, the field mask specifies areas of the grass field that should not be rendered.
• If used together with a Field Animation object, the field mask specifies areas of the grass field that should be animated.

Grass polygons oriented along normal of Grass object

Grass polygons oriented along normal of Terrain

Read more here.

Sets the ground slope angle.

• By the minimum value of 0, grass will grow everywhere on the ground.
• The bigger the value is, the flatter the place should be for grass to grow. So, as the value is increased, steep slopes turn out to be bare at first, and then low-sloped places also become grassless.
• By the maximum value of 1, grass will grow only on the strictly horizontal ground.

Flag indicating whether grass is thinned out with a distance.

• If the flag is set, random grass polygons are not rendered across the grass Fade distance.
• If the flag is not set, all grass polygons are rendered between the grass Visibility distance and the Fade distance.