My client sends a packet to activate an ability which generates a wall in front of it, layer by layer (on the Y axis) every tick. I would like to have the server place blocks every tick without sending updates to the clients, and every client in range to animate a block entity going upwards, then transforming into a block on every tick. How would I go about doing that?

Better yet, how do I animate them from the server? I know there is some kind of interpolation. How do I use it to animate the blocks in as few packets as possible?

I am analyzing falling blocks, but that will take some time to do. If anyone could provide any input, I would appreciate it.

I am finding the code difficult to read. Can anyone give me an example of a block, similar to sand, that, when placed, turns into and entity, goes up one block, then turns back into a block?

I would do it by creating a subclass of FallingBlock (if it is still called that) and adding a targetHeight field, then making the block "fall" or "rise" to meet that height, before turning into the specified block. That way most of the code should be reusable from the parent class.

You will have to register it as a new EntityType.

Then when your block rises, you create a new instance of your entity, with the targetHeight one block higher than the current y position.

14 minutes ago, Alpvax said:

I would do it by creating a subclass of FallingBlock (if it is still called that) and adding a targetHeight field, then making the block "fall" or "rise" to meet that height, before turning into the specified block. That way most of the code should be reusable from the parent class.

You will have to register it as a new EntityType.

Then when your block rises, you create a new instance of your entity, with the targetHeight one block higher than the current y position.

I am not sure I follow. How would I make the block "fall" or "rise"?

In the "tick" method , you need to set the y component of the deltaMovement to be positive (to rise) or negative (to fall). The exact value that you use will determine how fast.

//FallingBlockEntity uses the following values (when gravity is not disabled)
//by adding the velocity, it allows the entity to have smooth movement and allows directions other than straight down
this.setDeltaMovement(this.getDeltaMovement().add(0.0D, -0.04D, 0.0D));

Looking at the tick method of the FallingBlockEntity class it may give you a better idea of how it works.

Edited November 30, 20213 yr by Alpvax
Looked up method names and removed obsolete info

19 hours ago, Alpvax said:

In the "tick" method , you need to set the y component of the deltaMovement to be positive (to rise) or negative (to fall). The exact value that you use will determine how fast.

//FallingBlockEntity uses the following values (when gravity is not disabled)
//by adding the velocity, it allows the entity to have smooth movement and allows directions other than straight down
this.setDeltaMovement(this.getDeltaMovement().add(0.0D, -0.04D, 0.0D));

Looking at the tick method of the FallingBlockEntity class it may give you a better idea of how it works.

Thanks, but I had already solved it.

On 11/30/2021 at 4:39 PM, Alpvax said:

In the "tick" method , you need to set the y component of the deltaMovement to be positive (to rise) or negative (to fall). The exact value that you use will determine how fast.

//FallingBlockEntity uses the following values (when gravity is not disabled)
//by adding the velocity, it allows the entity to have smooth movement and allows directions other than straight down
this.setDeltaMovement(this.getDeltaMovement().add(0.0D, -0.04D, 0.0D));

Looking at the tick method of the FallingBlockEntity class it may give you a better idea of how it works.

I have another issue. Let me explain my use of the entity.

The server is spawning that entity, that just goes upwards. When it reaches the position of the block above,  it deletes itself. At that time, the entity will place a block there. 

This entity is spawned only on the client, using a packet. Multiple may be spawned at a time. 

I haven't made the entity place the blocks yet, because I ran into an issue. 

My game bugs out randomly, when spawning these entities. My modded overlay disappears, my placer stops moving and oscillates back and forth, and I can't do anything. 

public class MudWallBlockEntity extends Entity {
    private BlockPos startingBlockPos;
    private BlockState blockState;

    private int ticks;

    public MudWallBlockEntity(EntityType<? extends MudWallBlockEntity> entityType, World level){
        super(entityType, level);
    }

    public MudWallBlockEntity(EntityType<? extends MudWallBlockEntity> entityType, World level, BlockPos position, BlockState block){
        super(entityType, level);
        this.startingBlockPos = position;
        this.blockState = block;

        this.setPos(position.getX(), position.getY(), position.getZ());
        this.ticks = 0;
    }

    @Override
    protected void defineSynchedData() { }

    @Override
    protected void readAdditionalSaveData(@Nonnull CompoundNBT pCompound) { }

    @Override
    protected void addAdditionalSaveData(@Nonnull CompoundNBT pCompound) { }

    @Override
    public IPacket<?> getAddEntityPacket() {
        LogManager.getLogger().error("THE GAME CRASHED BECAUSE THE /SUMMON COMMAND WAS USED TO SUMMON MudWallBlockEntity!");
        return null;
    }

    @Override
    public void tick() {
        if(ticks++ == 0){
            // the entity was placed into the world.
        }
        LogManager.getLogger().info("ticks: " + ticks);
        if(blockPosition().getY() >= startingBlockPos.getY()){
            remove();
            return;
        }

        setDeltaMovement(0, 0.05, 0);
        move(MoverType.SELF, getDeltaMovement());
    }

    public BlockState getBlockState() {
        return blockState;
    }

    public BlockPos getStartingBlockPos(){
        return startingBlockPos;
    }

    @Override
    public boolean canBeCollidedWith() {
        return false;
    }

    @Override
    protected boolean canAddPassenger(Entity pPassenger) {
        return false;
    }

    @Override
    public boolean canChangeDimensions() {
        return false;
    }
}

public class MudWallBlockEntityRenderer  extends EntityRenderer<MudWallBlockEntity> {
    public MudWallBlockEntityRenderer(EntityRendererManager entityRendererManager) {
        super(entityRendererManager);
        this.shadowRadius = 0.5F;
    }

    @Override
    public void render(MudWallBlockEntity entity, float entityYaw, float partialTicks, MatrixStack matrixStack, IRenderTypeBuffer buffer, int packedLight) {
        BlockState blockstate = entity.getBlockState();
        if (blockstate.getRenderShape() == BlockRenderType.MODEL) {
            World world = entity.getCommandSenderWorld();
            if (blockstate != world.getBlockState(entity.blockPosition()) && blockstate.getRenderShape() != BlockRenderType.INVISIBLE) {
                matrixStack.pushPose();
                BlockPos blockpos = new BlockPos(entity.getX(), entity.getBoundingBox().maxY, entity.getZ());
                matrixStack.translate(-0.5D, 0.0D, -0.5D);
                BlockRendererDispatcher blockrendererdispatcher = Minecraft.getInstance().getBlockRenderer();
                for (net.minecraft.client.renderer.RenderType type : net.minecraft.client.renderer.RenderType.chunkBufferLayers()) {
                    if (RenderTypeLookup.canRenderInLayer(blockstate, type)) {
                        net.minecraftforge.client.ForgeHooksClient.setRenderLayer(type);
                        blockrendererdispatcher.getModelRenderer().tesselateBlock(world, blockrendererdispatcher.getBlockModel(blockstate), blockstate, blockpos, matrixStack,buffer.getBuffer(type), false, new Random(), blockstate.getSeed(entity.getStartingBlockPos()), OverlayTexture.NO_OVERLAY);
                    }
                }
                net.minecraftforge.client.ForgeHooksClient.setRenderLayer(null);
                matrixStack.popPose();
                super.render(entity, entityYaw, partialTicks, matrixStack, buffer, packedLight);
            }
        }
    }

    @Override
    public ResourceLocation getTextureLocation(MudWallBlockEntity pEntity) {
        return AtlasTexture.LOCATION_BLOCKS;
    }
}

Spawning code:

public static void handlePacket(ServerSpawnMudWallEntityPacket message, Supplier<NetworkEvent.Context> ctx) {
    PlayerEntity player = (PlayerEntity) Minecraft.getInstance().cameraEntity;
    ClientWorld level = (ClientWorld) (player.getCommandSenderWorld());
    for(Tuple<BlockPos, UUID> spawnData : message.getSpawnList()){
        BlockPos blockPos = spawnData.getFirst();
        UUID uuid = spawnData.getSecond();
        MudWallBlockEntity entity = new MudWallBlockEntity(
                ModEntities.MUD_WALL_BLOCK_ENTITY.get(),
                level,
                blockPos,
                ModBlocks.TEMPORARY_DIRT_BLOCK.get().defaultBlockState());
        entity.setPacketCoordinates(blockPos.getX(), blockPos.getY(), blockPos.getZ());
        entity.moveTo(blockPos, 0f, 0f);
        entity.setUUID(uuid);
        level.putNonPlayerEntity(entities++, entity);
    }
}

The UUID is just UUID.getRandom. "entities" is an integer.

The value printed in the entity tick is one tick (so the method ran once before doing entity.remove())

Here is what happens:

https://streamable.com/mc98kl

 

On 12/4/2021 at 4:11 PM, matthew123 said:

This entity is spawned only on the client

Why?

 

On 12/4/2021 at 4:11 PM, matthew123 said:

if(blockPosition().getY() >= startingBlockPos.getY()){
            remove();
            return;
        }

If it has moved so it is above where it started, stop. That's why your tick method only runs once.

 

I imagine that things are going wrong because you're using a client-side only Entity. Just do what the FallingBlockEntity does and use the same Entity both sides