What effect can you NOT add directly to a vector layer?

The blur effect cannot be added directly to a vector layer in Storyboard Pro. This is because vector layers are typically designed to maintain quality at any resolution and are made up of paths and shapes that are mathematically defined. The blur effect, which modifies the edges of shapes, requires rasterization—converting vector elements into pixel-based images to create the blurred look. This rasterization process often compromises the scalability and quality that vectors offer.

In contrast, effects like shadows, strokes, and fills can be applied to vector layers because they either enhance the existing vector paths or are compatible with the vector system. Shadows can add depth to the objects, strokes can outline vector shapes, and fills can provide color or pattern to the interior of the shapes without turning them into pixels. Therefore, the nature of vector graphics makes the blur effect incompatible as a direct addition, emphasizing the distinction between vector-based and raster-based effects.