Working with Layers			Using Parenting Axes
Chapter 8, Multilayer Compositing and 3D Effects

When you create a layer, you are assigning a source input to a geometric object that defines the surface on which the source is mapped. You can replace the assigned surface object with a different one, as well as disconnect a surface object in the Schematic and replace it with another. By default, when you create a layer, the surface type is determined by the last geometric setting chosen in the Layer Editor.

Note: When you create a layer in the Schematic view, the default surface is Bilinear.

There are five surface types available in Reaction: bilinear, box, frustum, sphere, and plane. The bilinear surface is a planar surface with four vertices, one at each corner. The vertices are joined by straight line segments using linear interpolation. The box, frustum, and sphere surfaces are 3D primitives meshes with no control vertices.

Modifying Surface Shape and Geometry

You can change a surface's shape by scaling it using the transformation tools. You can also modify a surface's base geometry from the Surfaces tab in the Reaction tool UI. You can increase or decrease the number of segments to change the number and shape of the surface's polygons, which may affect its shape, how it reacts to lights in the scene, and how texture maps are displayed.

Hint: You can toggle the display of the icons that represent the camera, lights, axis, and transformation by selecting Icons on the Render tab.

1. Select the Surfaces tab.

2. Select a layer from the Layer Editor.

3. To change the surface, select a surface type under the Type column.

4. In the Surfaces tab, adjust the properties to modify the surface's geometry.

   Surface Type	Description
   Bilinear	You can change the number of segments to increase or decrease the number of polygons, and change their shape. You can also move corner points in X, Y, and Z to create a variety of 4-sided shapes. Because you can also move corners in Z, you can create warped effects.
   Box	You can change the number and size of segments to increase or decrease the number of polygons, and change their shape.
   Frustum	You can change the geometry of the top, bottom, and height, as well as the number of segments to increase or decrease the number of polygons.
   Plane	You can change the number of segments to increase or decrease the number of polygons, and change their shape.
   Sphere	You can change the number of segments to increase or decrease the number of polygons, and modify the smoothness of the sphere, or change its shape. When you reduce the number of segments, you will create a more faceted appearing sphere that will also affect how it reacts to lights. You can also modify the radius to change the size of the sphere.

   
   
   

1. In the Layer Editor, select a layer with a Bilinear surface.

2. Select the Surfaces tab.

   In the Player, manipulators appear at each corner of the surface.

   

3. Adjust the manipulators to modify the surface.

   Hint: You can also select a bilinear surface by opening the Group Schematic.