Kltyton Bedrock Runtime

Introduction

Kltyton Bedrock Runtime, or KBR, also goes by GeckoLib++, although I don’t think this mess of code I’ve written quite deserves that name.

It started as a shared library providing code support for kltyton’s own mods. It used to be bundled inside those mods through Jar-in-Jar. As the library grew, bundling it made the mod files too large, so I decided to release it as a standalone mod.

Built on GeckoLib’s model resources, renderers and animation ecosystem, KBR adds animation graphs, polygon geometry, Bedrock particles, and model-derived part selection and collision.

Features

Continuous animation blending: BlendSpaces similar to those in Unreal Engine. A 1D BlendSpace can blend idle, walking and running, while a 2D BlendSpace can drive directional movement and aiming.

Layered poses: Apply masks to individual bones or entire subtrees, combine ordinary and additive poses, and optionally use Hermite transitions driven by explicit start and end velocities.

Tree and Baked models: Preserve logical bones and locators, organize geometry, and explicitly declare static structures that can be merged.

Bedrock mesh models: Support the triangle-based mesh geometry used by Bedrock models.

Bedrock particles and Molang: Load effects, expressions, curves and events from JSON. Support Bedrock/Snowstorm-style billboard particles and 3D model particles using ordinary cubes, GeckoLib models or enhanced polygon models.

Model-part selection and collision: Register participating bones, select and highlight parts, handle attack and contact events, store per-part data, and query recent geometry on the server. Entity movement collision uses oriented bounding boxes (OBBs).

Model-based blocks: Generate AABB/OBB shapes from models and build automatic multi-block structures through the APIs provided for the corresponding version.

Getting started

For a quick introduction, see the installation guide and developer setup. More detailed documentation is available in the Wiki.

Source code and issue tracking are available in the project repository.

Credits and license

KBR is licensed under LGPL-3.0-only. GeckoLib is a required external dependency. Its model, animation and particle features reference or reuse work from SimpleBedrockModel, MAE, ParticleStorm, ThreeDimensionParticle and mochafloats. Original license and attribution notices are retained in the source and distribution.