Simplifying Shapes

Simplifying shapes

Sometimes an exact shape contains far more boxes than an outline needs. VoxLib has three helpers that trade accuracy for fewer boxes.

That trade is real: simplification fills some empty space and changes the geometry. Keep the original shape for collision, raycasting, and anything else that must be exact. Use the simplified copy only where a rougher outline is acceptable.

simplifyForOutline

Reduces a shape to at most maxBoxes boxes (default 8) by filling some empty space:

import com.github.mystery2099.voxlib.combination.VoxelAssembly.simplifyForOutline
import com.github.mystery2099.voxlib.shapes.CommonShapes

val collisionShape = CommonShapes.createTable()
val outlineShape = collisionShape.simplifyForOutline(maxBoxes = 8)

A common pairing keeps both:

companion object {
    val COLLISION = CommonShapes.createTable()
    val OUTLINE = COLLISION.simplifyForOutline()
}

toBoundingBoxShape

Collapses a shape to its bounding box in one call:

import com.github.mystery2099.voxlib.combination.VoxelAssembly.toBoundingBoxShape

val looseOutline = complexShape.toBoundingBoxShape()

This is the blunt option. Use it when one loose box is good enough, such as a quick preview outline.

createOutlineShape

Builds a hollow box directly, without starting from another shape:

import com.github.mystery2099.voxlib.combination.VoxelAssembly.createOutlineShape

val hollow = createOutlineShape(
    minX = 0, minY = 0, minZ = 0,
    maxX = 16, maxY = 16, maxZ = 16,
    thickness = 1
)

The result is six thin panels forming the walls of the given volume, with the wall thickness controlled by thickness (default 1 block-unit). This shape is still assembled with vanilla VoxelShape operations; it is not intrinsically cheaper than a solid cuboid, it just has a hollow profile.

Limits and validation

• maxBoxes must be at least 1. Other values throw IllegalArgumentException.
• Empty input shapes are handled: bounding-box simplification of an empty shape is safe.
• Simplification is not cached the way unions and transformations are. Store simplified results in constants like any other fixed shape.

When not to simplify

Do not use a simplified shape where exact geometry matters. In particular:

• getShape / getCollisionShape overrides: use the exact shape.
• Raycasting or clip behavior: use the exact shape.
• Comparisons with vanilla shapes: use the exact shape.

The approximate result fills empty space between boxes, which changes isFull, collision responses, and outline silhouettes.