Block Entity Rendering

Block Entity Rendering

This guide covers advanced block entity rendering techniques beyond basic setup. Block entities (formerly Tile Entities) are special blocks with custom rendering and data storage.

Advanced Block Entity Rendering

Conditional Rendering

Render different appearances based on block entity state:

// Example: Adaptive block entity renderer
public class AdaptiveBlockEntityRenderer implements BlockEntityRenderer<AdaptiveBlockEntity> {
    private final AdaptiveModel model;
    private final Map<String, ResourceLocation> textures = new HashMap<>();

    public AdaptiveBlockEntityRenderer(BlockEntityRendererProvider.Context context) {
        this.model = new AdaptiveModel(context.bakeLayer(AdaptiveModel.LAYER_LOCATION));
        loadTextures();
    }

    @Override
    public void render(AdaptiveBlockEntity blockEntity, float partialTick,
                      PoseStack poseStack, MultiBufferSource bufferSource,
                      int light, int overlay) {

        poseStack.pushPose();
        poseStack.translate(0.5, 0.5, 0.5);

        // Select rendering mode based on state
        switch (blockEntity.getRenderMode()) {
            case NORMAL:
                renderNormalMode(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
            case POWERED:
                renderPoweredMode(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
            case DAMAGED:
                renderDamagedMode(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
            case ACTIVE:
                renderActiveMode(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
        }

        poseStack.popPose();
    }

    private void renderActiveMode(AdaptiveBlockEntity blockEntity, float partialTick,
                                 PoseStack poseStack, MultiBufferSource bufferSource,
                                 int light, int overlay) {

        // Render base block
        model.renderBase(poseStack, bufferSource.getBuffer(getRenderType("base")), light, overlay);

        // Add pulsing glow effect
        float pulseIntensity = Mth.sin(blockEntity.getActivationTime() * 0.1f) * 0.3f + 0.7f;

        poseStack.pushPose();
        poseStack.scale(1.1f + pulseIntensity * 0.1f, 1.1f + pulseIntensity * 0.1f,
                     1.1f + pulseIntensity * 0.1f);

        model.renderGlow(poseStack,
                       bufferSource.getBuffer(getRenderType("glow")),
                       0xF000F0, overlay, pulseIntensity);

        poseStack.popPose();

        // Add particle effects
        renderActiveParticles(blockEntity, partialTick, poseStack, bufferSource);
    }

    private void renderActiveParticles(AdaptiveBlockEntity blockEntity, float partialTick,
                                    PoseStack poseStack, MultiBufferSource bufferSource) {

        // Render floating energy particles
        float time = blockEntity.getActivationTime() + partialTick;

        for (int i = 0; i < 8; i++) {
            float angle = (float) (i * Math.PI * 2.0 / 8.0) + time * 0.02f;
            float height = Mth.sin(time * 0.1f + i) * 0.3f + 0.5f;

            poseStack.pushPose();
            poseStack.translate(Mth.cos(angle) * 0.7, height, Mth.sin(angle) * 0.7);

            float particlePulse = Mth.sin(time * 0.2f + i) * 0.2f + 0.8f;
            renderEnergyParticle(poseStack, bufferSource, particlePulse);

            poseStack.popPose();
        }
    }
}

Dynamic Model Generation

Generate models procedurally based on block entity data:

// Example: Dynamic model generation
public class DynamicBlockEntityRenderer implements BlockEntityRenderer<DynamicBlockEntity> {
    private final Map<Integer, BakedModel> cachedModels = new HashMap<>();
    private final ModelBaker modelBaker;

    public DynamicBlockEntityRenderer(BlockEntityRendererProvider.Context context) {
        this.modelBaker = context.getModelBaker();
    }

    @Override
    public void render(DynamicBlockEntity blockEntity, float partialTick,
                      PoseStack poseStack, MultiBufferSource bufferSource,
                      int light, int overlay) {

        poseStack.pushPose();
        poseStack.translate(0.5, 0.5, 0.5);

        // Generate or get cached model
        BakedModel model = getDynamicModel(blockEntity);

        // Render with custom transformation
        poseStack.mulPose(Axis.YP.rotationDegrees(blockEntity.getRotation()));
        poseStack.scale(blockEntity.getScale(), blockEntity.getScale(), blockEntity.getScale());

        // Extract model geometry and render
        renderBakedModel(model, poseStack, bufferSource, light, overlay, blockEntity);

        poseStack.popPose();
    }

    private BakedModel getDynamicModel(DynamicBlockEntity blockEntity) {
        int configurationHash = blockEntity.getConfigurationHash();

        return cachedModels.computeIfAbsent(configurationHash, hash -> {
            return generateDynamicModel(blockEntity);
        });
    }

    private BakedModel generateDynamicModel(DynamicBlockEntity blockEntity) {
        // Create model elements based on block entity configuration
        List<SimpleBakedModel.Builder> elements = new ArrayList<>();

        // Generate core structure
        elements.add(generateCoreElement(blockEntity.getCoreType()));

        // Add decorative elements
        for (int i = 0; i < blockEntity.getDecorationCount(); i++) {
            elements.add(generateDecorationElement(blockEntity.getDecoration(i), i));
        }

        // Add connection elements
        for (Direction direction : blockEntity.getConnectedDirections()) {
            elements.add(generateConnectionElement(direction));
        }

        // Bake the model
        return modelBaker.bake(elements, ModelRotation.X0_Y0);
    }

    private void renderBakedModel(BakedModel model, PoseStack poseStack,
                                MultiBufferSource bufferSource, int light, int overlay,
                                DynamicBlockEntity blockEntity) {

        Random random = new Random();
        long seed = 42L; // Fixed seed for consistent rendering

        for (RenderType renderType : model.getRenderTypes(blockEntity, random)) {
            VertexConsumer consumer = bufferSource.getBuffer(renderType);

            // Render model with proper lighting and color
            model.renderModel(poseStack.last().pose(), consumer,
                           light, overlay, blockEntity.getColor(),
                           blockEntity.getAlpha(), seed, OverlayTexture.NO_OVERLAY);
        }
    }
}

Connected Texture Rendering

Handle block entities that connect to neighbors:

// Example: Connected texture rendering
public class ConnectedBlockEntityRenderer implements BlockEntityRenderer<ConnectedBlockEntity> {
    private final ConnectedModel model;
    private final ResourceLocation connectionTexture;

    public ConnectedBlockEntityRenderer(BlockEntityRendererProvider.Context context) {
        this.model = new ConnectedModel(context.bakeLayer(ConnectedModel.LAYER_LOCATION));
        this.connectionTexture = new ResourceLocation("connectedmod", "block/connections");
    }

    @Override
    public void render(ConnectedBlockEntity blockEntity, float partialTick,
                      PoseStack poseStack, MultiBufferSource bufferSource,
                      int light, int overlay) {

        poseStack.pushPose();
        poseStack.translate(0.5, 0.5, 0.5);

        // Analyze connections to neighbors
        ConnectionMap connections = analyzeConnections(blockEntity);

        // Render base block
        model.renderBase(poseStack, bufferSource.getBuffer(RenderType.solid()), light, overlay);

        // Render connection faces
        renderConnections(blockEntity, connections, poseStack, bufferSource, light, overlay);

        // Render center connector
        renderCenterConnector(blockEntity, poseStack, bufferSource, light, overlay);

        poseStack.popPose();
    }

    private ConnectionMap analyzeConnections(ConnectedBlockEntity blockEntity) {
        ConnectionMap connections = new ConnectionMap();
        BlockPos pos = blockEntity.getBlockPos();
        Level level = blockEntity.getLevel();

        for (Direction direction : Direction.values()) {
            BlockPos neighborPos = pos.relative(direction);
            BlockState neighborState = level.getBlockState(neighborPos);
            BlockEntity neighborEntity = level.getBlockEntity(neighborPos);

            if (canConnect(blockEntity, neighborState, neighborEntity, direction)) {
                connections.setConnection(direction, getConnectionType(blockEntity, neighborEntity, direction));
            }
        }

        return connections;
    }

    private void renderConnections(ConnectedBlockEntity blockEntity, ConnectionMap connections,
                                 PoseStack poseStack, MultiBufferSource bufferSource,
                                 int light, int overlay) {

        for (Direction direction : connections.getConnectedDirections()) {
            ConnectionType connectionType = connections.getConnection(direction);

            poseStack.pushPose();

            // Position connection face
            poseStack.translate(direction.getStepX() * 0.5, direction.getStepY() * 0.5,
                           direction.getStepZ() * 0.5);

            // Rotate to face correct direction
            poseStack.mulPose(getRotationForDirection(direction));

            // Render connection based on type
            switch (connectionType) {
                case STRAIGHT:
                    model.renderStraightConnection(poseStack, bufferSource.getBuffer(getConnectionRenderType()),
                                             light, overlay);
                    break;
                case CORNER:
                    model.renderCornerConnection(poseStack, bufferSource.getBuffer(getConnectionRenderType()),
                                           light, overlay);
                    break;
                case CROSS:
                    model.renderCrossConnection(poseStack, bufferSource.getBuffer(getConnectionRenderType()),
                                           light, overlay);
                    break;
            }

            poseStack.popPose();
        }
    }
}

Advanced Lighting Techniques

Custom Light Emission

Block entities that emit light:

// Example: Light-emitting block entity renderer
public class LightEmittingBlockEntityRenderer implements BlockEntityRenderer<LightBlockEntity> {
    private final LightModel model;
    private final RenderTarget lightRenderTarget;
    private final ShaderInstance lightShader;

    public LightEmittingBlockEntityRenderer(BlockEntityRendererProvider.Context context) {
        this.model = new LightModel(context.bakeLayer(LightModel.LAYER_LOCATION));

        // Setup render target for light bloom effect
        this.lightRenderTarget = new RenderTarget(256, 256, true, false);

        try {
            this.lightShader = new ShaderInstance(
                Minecraft.getInstance().getResourceManager(),
                "light_emission",
                DefaultVertexFormat.POSITION_COLOR_TEX
            );
        } catch (IOException e) {
            throw new RuntimeException("Failed to load light shader", e);
        }
    }

    @Override
    public void render(LightBlockEntity blockEntity, float partialTick,
                      PoseStack poseStack, MultiBufferSource bufferSource,
                      int light, int overlay) {

        poseStack.pushPose();
        poseStack.translate(0.5, 0.5, 0.5);

        // Calculate light intensity based on entity state
        float lightIntensity = calculateLightIntensity(blockEntity, partialTick);

        // Render base model with normal lighting
        model.renderBase(poseStack, bufferSource.getBuffer(RenderType.solid()), light, overlay);

        // Render light effect with additive blending
        renderLightEffect(blockEntity, lightIntensity, poseStack, bufferSource);

        poseStack.popPose();
    }

    private void renderLightEffect(LightBlockEntity blockEntity, float lightIntensity,
                                PoseStack poseStack, MultiBufferSource bufferSource) {

        // Enable additive blending for light effect
        RenderSystem.enableBlend();
        RenderSystem.blendFunc(GlStateManager.SourceFactor.SRC_ALPHA,
                             GlStateManager.DestFactor.ONE);
        RenderSystem.disableDepthTest();

        // Setup light shader
        setupLightShader(blockEntity, lightIntensity);

        // Render glowing core
        poseStack.pushPose();

        float pulseScale = 1.0f + Mth.sin(blockEntity.getAnimationTime() * 0.1f) * 0.1f;
        poseStack.scale(pulseScale, pulseScale, pulseScale);

        model.renderLightCore(poseStack, bufferSource.getBuffer(getLightRenderType()),
                           0xF000F0, OverlayTexture.NO_OVERLAY, lightIntensity);

        poseStack.popPose();

        // Render light rays
        renderLightRays(blockEntity, lightIntensity, poseStack, bufferSource);

        // Restore render state
        RenderSystem.enableDepthTest();
        RenderSystem.disableBlend();

        // Clear shader
        lightShader.clear();
    }

    private void renderLightRays(LightBlockEntity blockEntity, float lightIntensity,
                                PoseStack poseStack, MultiBufferSource bufferSource) {

        float time = blockEntity.getAnimationTime();
        VertexConsumer consumer = bufferSource.getBuffer(getLightRenderType());
        Matrix4f matrix = poseStack.last().pose();

        // Render animated light rays
        for (int i = 0; i < 12; i++) {
            float angle = (float) (i * Math.PI * 2.0 / 12.0) + time * 0.01f;
            float rayLength = 2.0f + Mth.sin(time * 0.1f + i) * 0.5f;
            float rayOpacity = lightIntensity * (0.3f + Mth.sin(time * 0.05f + i * 0.5f) * 0.2f);

            renderLightRay(matrix, consumer, angle, rayLength, rayOpacity);
        }
    }
}

Ambient Occlusion

Custom ambient occlusion for block entities:

// Example: Block entity with custom ambient occlusion
public class AmbientBlockEntityRenderer implements BlockEntityRenderer<AmbientBlockEntity> {
    private final AmbientModel model;

    @Override
    public void render(AmbientBlockEntity blockEntity, float partialTick,
                      PoseStack poseStack, MultiBufferSource bufferSource,
                      int light, int overlay) {

        poseStack.pushPose();
        poseStack.translate(0.5, 0.5, 0.5);

        // Calculate ambient occlusion based on neighbors
        float[] aoValues = calculateAmbientOcclusion(blockEntity);

        // Render with custom lighting
        renderWithAmbientOcclusion(blockEntity, aoValues, poseStack, bufferSource, light, overlay);

        poseStack.popPose();
    }

    private float[] calculateAmbientOcclusion(AmbientBlockEntity blockEntity) {
        BlockPos pos = blockEntity.getBlockPos();
        Level level = blockEntity.getLevel();
        float[] aoValues = new float[6]; // One for each face

        for (Direction direction : Direction.values()) {
            aoValues[direction.ordinal()] = calculateFaceAO(level, pos, direction);
        }

        return aoValues;
    }

    private float calculateFaceAO(Level level, BlockPos pos, Direction face) {
        float ao = 0.0f;
        int count = 0;

        // Check surrounding blocks for AO calculation
        for (Direction neighbor : getNeighborDirections(face)) {
            BlockPos neighborPos = pos.relative(neighbor);
            BlockState neighborState = level.getBlockState(neighborPos);

            if (!neighborState.isSolidRender(level, neighborPos)) {
                ao += 1.0f;
            }
            count++;
        }

        if (count > 0) {
            ao /= count;
        }

        return ao;
    }

    private void renderWithAmbientOcclusion(AmbientBlockEntity blockEntity, float[] aoValues,
                                           PoseStack poseStack, MultiBufferSource bufferSource,
                                           int light, int overlay) {

        // Render each face with calculated AO
        for (Direction direction : Direction.values()) {
            if (shouldRenderFace(blockEntity, direction)) {
                float ao = aoValues[direction.ordinal()];
                float modifiedLight = modifyLightForAO(light, ao);

                poseStack.pushPose();

                // Position and rotate for face
                poseStack.translate(direction.getStepX() * 0.49, direction.getStepY() * 0.49,
                               direction.getStepZ() * 0.49);
                poseStack.mulPose(getRotationForFace(direction));

                // Render face with AO-modified lighting
                model.renderFace(poseStack, direction, bufferSource.getBuffer(RenderType.cutout()),
                                modifiedLight, overlay, ao);

                poseStack.popPose();
            }
        }
    }

    private float modifyLightForAO(int light, float ao) {
        // Extract sky and block light
        int skyLight = (light >> 20) & 0xF;
        int blockLight = light & 0xF;

        // Apply AO to block light more strongly
        skyLight = (int) (skyLight * (0.8f + ao * 0.2f));
        blockLight = (int) (blockLight * (0.6f + ao * 0.4f));

        return (skyLight << 20) | blockLight;
    }
}

Performance Optimization

Chunk-based Culling

Optimize rendering based on chunk visibility:

// Example: Chunk-aware block entity renderer
public class ChunkOptimizedRenderer implements BlockEntityRenderer<ChunkAwareBlockEntity> {
    private final Set<ChunkPos> visibleChunks = new HashSet<>();
    private long lastChunkUpdate = 0;

    @Override
    public void render(ChunkAwareBlockEntity blockEntity, float partialTick,
                      PoseStack poseStack, MultiBufferSource bufferSource,
                      int light, int overlay) {

        // Early-out based on chunk visibility
        if (!isChunkVisible(blockEntity)) {
            return;
        }

        // Distance-based LOD
        double distanceSquared = getDistanceToPlayerSquared(blockEntity);
        int lodLevel = getLODLevel(distanceSquared);

        switch (lodLevel) {
            case 0: // High detail
                renderHighDetail(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
            case 1: // Medium detail
                renderMediumDetail(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
            case 2: // Low detail
                renderLowDetail(blockEntity, partialTick, poseStack, bufferSource, light, overlay);
                break;
        }
    }

    private boolean isChunkVisible(ChunkAwareBlockEntity blockEntity) {
        ChunkPos chunkPos = new ChunkPos(blockEntity.getBlockPos());

        // Update visible chunks periodically
        long currentTime = System.currentTimeMillis();
        if (currentTime - lastChunkUpdate > 100) { // Update every 100ms
            updateVisibleChunks();
            lastChunkUpdate = currentTime;
        }

        return visibleChunks.contains(chunkPos);
    }

    private void updateVisibleChunks() {
        visibleChunks.clear();

        Minecraft minecraft = Minecraft.getInstance();
        if (minecraft.player != null && minecraft.level != null) {
            ChunkPos playerChunk = new ChunkPos(minecraft.player.blockPosition());
            int renderDistance = minecraft.options.renderDistance;

            // Add all visible chunks
            for (int x = -renderDistance; x <= renderDistance; x++) {
                for (int z = -renderDistance; z <= renderDistance; z++) {
                    visibleChunks.add(new ChunkPos(playerChunk.x + x, playerChunk.z + z));
                }
            }
        }
    }
}

Common Issues and Solutions

Rendering Artifacts

Problem: Block entity flickering or disappearing Solution: Use proper culling and depth handling

// Example: Proper culling setup
public void renderWithProperCulling(BlockEntity blockEntity, PoseStack poseStack,
                                    MultiBufferSource bufferSource, int light, int overlay) {

    // Only render if facing player (optimization)
    Vec3 toPlayer = Minecraft.getInstance().player.getEyePosition()
                                   .subtract(Vec3.atCenterOf(blockEntity.getBlockPos()));
    Direction facing = blockEntity.getBlockState().getValue(BlockStateProperties.FACING);

    if (toPlayer.dot(facing.getNormal()) < 0) {
        return; // Don't render back faces
    }

    // Render with proper depth handling
    RenderSystem.enableDepthTest();
    RenderSystem.depthFunc(GL11.GL_LEQUAL);

    // Normal rendering
    renderBlockEntity(blockEntity, poseStack, bufferSource, light, overlay);
}

Texture Animation Issues

Problem: Animated textures not updating smoothly Solution: Use proper UV animation

// Example: Smooth texture animation
public void renderWithAnimatedTexture(BlockEntity blockEntity, float partialTick,
                                   PoseStack poseStack, MultiBufferSource bufferSource) {

    // Calculate animation frame
    float animationSpeed = 0.1f; // Frames per second
    float animationTime = (blockEntity.getTickCount() + partialTick) * animationSpeed;
    int frameCount = 8; // Number of animation frames
    int currentFrame = (int) (animationTime % frameCount);

    // Calculate UV coordinates for current frame
    float frameWidth = 1.0f / frameCount;
    float uOffset = currentFrame * frameWidth;

    // Render with animated UVs
    VertexConsumer consumer = bufferSource.getBuffer(getAnimatedRenderType());

    for (Vertex vertex : getBlockEntityVertices()) {
        consumer.addVertex(poseStack.last().pose(), vertex.x, vertex.y, vertex.z)
               .setColor(vertex.color)
               .setUv(vertex.u * frameWidth + uOffset, vertex.v)
               .setLight(vertex.light)
               .setNormal(vertex.normal);
    }
}

Best Practices

1. Use conditional rendering based on block entity state
2. Implement proper LOD for distant block entities
3. Apply custom lighting for special effects
4. Use chunk-based culling for performance
5. Handle texture animation smoothly with partial ticks
6. Implement proper culling to avoid unnecessary rendering
7. Cache models for dynamic block entities

Next Steps

• Resource Management - Managing GPU resources efficiently
• Performance Optimization - Advanced optimization techniques
• Complete Examples - Full working block entity examples