Mesh Rendering

FoundryEngine includes a custom 3D rendering engine alongside OBJ model support for GPU rendering outside Minecraft's standard pipeline.

Note: This API is Java-only.

MeshRenderer

The MeshRenderer (access via Client.getMeshRenderer()) provides two rendering paths:

Immediate draw

Client.getMeshRenderer().draw(pipeline, modelView, buffer -> {
    buffer.addVertex(pose, x, y, z)
        .setColor(r, g, b, a)
        .setNormal(pose, nx, ny, nz);
});

Begin/DrawSession

try (var session = Client.getMeshRenderer().begin(pipeline, modelView)) {
    session.withTexture("Sampler0", textureView, sampler);
    var buffer = session.buffer();
    buffer.addVertex(...);
}

Built-in pipelines

Pipeline	Vertex Format	Use Case
POSITION	Position only	Uncolored geometry
POSITION_COLOR	Position + Color	Colored geometry
POSITION_COLOR_NORMAL	Position + Color + Normal	Lit models
POSITION_TEX_COLOR	Position + UV + Color	Textured geometry
DEBUG_LINES	Position + Color + Normal + Line Width	Debug lines
FILLED_THROUGH_WALLS	Position + Color	Always-visible overlays

OBJ models

Loading

var model = new ObjModel(Common.id("models/suzanne.obj"));
Client.getObjModelManager().registerObjModel(model);

Rendering

model.renderModel(viewMatrix, EngineRenderPipelines.POSITION_COLOR_NORMAL);
model.renderModel(viewMatrix, pipeline, r, g, b, a);
model.renderObjects(viewMatrix, pipeline);
model.getObject("Cube").render(pipeline, viewMatrix);

Transforms

Each ObjObject has independent position, rotation, and scale:

var obj = model.getObject("Cube");
obj.setPosition(10, 0, 0);
obj.setRotation(0, (float)Math.PI / 2, 0);
obj.setScale(2.0f);

Shaders

20+ shaders are bundled under assets/foundryengine/shaders/. Core shaders include:

Shader Pair	Purpose
core/position	Uncolored solid geometry
core/position_color	Vertex-colored
core/position_color_lit	Lit with normals
core/position_tex_color	Textured
core/lines	Line rendering

World gizmo utilities

// Render a box handle
WorldGizmo.renderBox(position, 0.125, Color.RED);

// Render a line
WorldGizmo.renderLine(from, to, Color.BLUE, 3);

// Render an outline box
WorldGizmo.renderOutline(aabb, Color.GREEN);

// Hit test
boolean hovered = WorldGizmo.isHovered(position, eye, look);

Next

• Post-Processing — shader effects
• Editor — in-world editing handles