Function create_sdf_model 

pub fn create_sdf_model(
    opcodes: &[u32],
    constants: &[f32],
    bounding_box: &BoundingBox,
) -> FFIResult<u64>

Creates an SDF model from a Saft program.

These can be rendered directly or used to define bones for skinned SDF models. A correct bounding box is required for now (later we will derive it from the program).