Metadata attributes

Metadata attributes allow you to store and retrieve arbitrary key-value pairs. Each attribute name must be unique within its scope to avoid conflicts. This metadata is used by viewers for rendering or by exporters when writing output to a file.

Key Properties

• Non-Destructive: Metadata does not change the mathematical definition of the geometry, only how it is processed or displayed.
• Inheritance: Depending on the exporter and renderer, metadata on a model may be inherited by its children unless overridden.

color attribute

The color attribute attaches a color to a model node. In a viewer and for some exporter, the model will be rendered in the specified color.

#[color = "#FFFFFF"]
c = std::geo2d::Circle(r = 42.0mm);

std::debug::assert_eq([c#color, (r = 1.0, g = 1.0, b = 1.0, a = 1.0)]);

You can access the color property using the # accessor.

resolution attribute

The resolution attribute defines the rendering fidelity of the model. It determines how a smooth mathematical curve is sampled and converted into discrete segments or triangle.

• Default: Typically 0.1mm.
• Percentage: Using a percentage scales the fidelity relative to the default. Note that higher resolution means a smaller step size:
  • 100% = 0.1mm (Default)
  • 200% =0.05mm` (Finer detail)
  • 50% = 0.2mm (Coarser detail)

This means the circle in the example below will be rendered with a resolution 0.05mm.

#[resolution = 200%]
c = std::geo2d::Circle(r = 42.0mm);

std::debug::assert_eq([c#resolution, 200%]);