- The mesh that is used for projection should contain a single surface. In case if the mesh contains several surfaces, only the one with the 0 index will be used. Thus, the area of the decal will differ from the initial mesh.
- The decals are always of the same size regardless of the projection box location relatively to the projection surface.
- The DecalMesh class to manage mesh decals via API
- A set of samples located in the data/samples/decals/ directory:
Creating a Mesh Decal#
To create a mesh decal:
- On the Menu bar, choose Create -> Decal -> Mesh.
- In the file dialog window that opens, choose a mesh for the decal:
An exported mesh should have less than 10000 polygons.
- Press Ok button and place the decal somewhere in the world (for the decal to be projected, the mesh should intersect the surface).
Editing a Mesh Decal#
In the Node tab of the Parameters window, you can adjust the following parameters of the mesh decal:
Projection parameters of the mesh decal:
|Radius||The height of the projection box along the Z axis, in units.
|Mesh||Path to the .mesh file on which the decal is based.|
Parameters common for all types of decals:
|Viewport Mask||A viewport mask, specifying if the decal can be seen in the camera's viewport.|
|Intersection Mask||The decal's intersection mask is used paired with the cutout intersection mask of clutters and grass to cut out the clutter or grass in the areas of intersection with the decal (e.g. can be used to remove grass from the surface of a road projected using decal).|
|Life time||A time period during which the decal is projected, in seconds.|
|Fade time||A time period during which the decal fades away (after its life time exceeds), in seconds.|
|Init time||A time period after which the decal is projected, in seconds.|
Parameters controlling decal's visibility depending on the distance:
|Min visibility||A minimum visibility distance, starting at which the decal begins to fade in and then becomes completely visible, in units.|
|Min Fade||A minimum fade-in distance, across which the decal smoothly becomes visible due to the alpha fading. It is counted starting from the minimum visibility distance value, in units.|
|Max visibility||A maximum visibility distance, starting at which the decal begins to fade out until becomes completely invisible, in units.|
|Max Fade||A maximum fade-out distance, across which the decal smoothly becomes invisible due to the alpha fading. It is counted starting from the maximum visibility distance value, in units.|
Texture Coordinates Transformation#
Decal's texture coordinates transformation (a texture atlas can also be used):
|Scale X||A texture scale along the X axis. For example, by the scale of 2 the texture is repeated twice on one decal.|
|Scale Y||A texture scale along the Y axis.|
|Translate X||A texture offset along the X axis. For example, by the offset of 0.5 along the X axis the texture is repositioned to the right (so that the edge of the texture is rendered in the center).|
|Translate Y||A texture scale along the Y axis.|
Setting a Material#
A material selection:
|Material||A new material of the decal.|