Shape Blending
Shape Blending is a method of creating and modeling 3D shapes using Signed Distance Fields (SDF) combined with Spline's polygonal-based system.
Unlike traditional methods such as Polygonal Modeling, SDFs describe shapes mathematically using distance functions. This allows for smooth blending and operations like union, subtraction, and intersections of shapes.
How to create a new Shape Blend group
Click on the "+" icon on the toolbar;
Select "Shape Blend" from the dropdown menu;
A Shape Blend group will be created with an initial Sphere primitive.
Key Operations in Shape Blending
Primitives
Create with primitive shapes: Cube, Sphere, Torus, and Cylinder. These are accessible from the toolbar when selecting a Shape Blend group.
Boolean Operations
When selecting a shape blend primitive, you can define how it behaves with other shapes:
Union: Combine two shapes.
Intersection: Keep only the overlapping parts of two shapes.
Subtraction: Remove one shape from another.
Blending
Seamlessly connect shapes together to form smooth, natural transitions and flowing designs. Each shape blend primitive allows you to override the blending value for greater precision and control.
Resolution
Adjust the resolution of the blended shapes from Low to Very High. Lower resolutions are faster, while higher resolutions provide greater detail at the cost of processing power.
Color
Material: Control the material for the entire blended shape uniformly.
Children: Control the material of each shape, blend primitive individually, and materials will blend seamlessly together. Only the color layer of the children will be considered.
Ordering Blend Shapes in the Outliner
The logic of the shape's outliner order relates to how shapes are processed and blended within a Signed Distance Field (SDF) system. The order in the outliner determines how operations like blending, union, subtraction, or intersections are applied.
Bottom-to-Top Operations
SDF shapes in the outliner are processed sequentially, starting from the bottom. A shape higher in the list will affect the shapes below it. For example, subtracting a shape will remove parts of the shapes below it.
Constraints
SDF shapes only operate within the boundaries defined by the green helper of shape blend groups. Be mindful of that area when creating your shapes.
Be mindful of performance: the system can become computationally expensive when working with a large number of shapes, especially at the highest resolution settings.
A creation limit may be reached if you use too many shape blend groups or an excessive number of individual shapes within those groups.
When using the “Material: Children” option, ensure that your shapes include a color layer at the bottom of the materials layer list. Note that only the color layer will work on individual shapes when this option is enabled.