Help with explosions (and sides)

[Syric]

I'm trying to make a block that has a chance of exploding when the player steps on it or mines it. However, I have an issue: if I allow the code to run on either side, then if the block explodes on the client side only it produces block glitches (as it's still there serverside). On the other hand, if I only allow the code to run on the server side, the block glitches vanish but the player takes no damage from the explosion. How can I resolve this?

Apologies if this is a basic question, I'm still a little wobbly on how to properly manage sides.

[warjort]

In general, the server is the correct side for non gui processing.

Doing things on the client means other players and the server won't know what you have done and will disagree about the state of the world, like your "glitch".

The client is only there to provide data for rendering and give the user "proxy" objects to the server to interact with.

Though you can do optimisations/logic on the client, e.g. ignoring the user if they try to  "strip bark" on stone. No need to ask the server for this.

[Syric]

explode() is called from a few other places as well, all with the same !level.isClientSide() wrapping.

public void stepOn(Level level, BlockPos pos, BlockState state, Entity entity) {
        if (!level.isClientSide()) {
            explode(level, pos, state,0.1F);
        }
        super.stepOn(level, pos, state, entity);
    }

    private void explode(Level level, BlockPos pos, BlockState state, float chance) {
        RandomSource rdm = RandomSource.create();
        chatPrint("Checking explosion with chance " + chance, level);
        if (rdm.nextFloat() < chance) {
            chatPrint("Exploding!", level);
            if (state.getValue(WEAK_VERSION)) {
                level.explode(null, pos.getX(), pos.getY(), pos.getZ(), 1.5F, Explosion.BlockInteraction.BREAK);
            } else {
                level.explode(null, pos.getX(), pos.getY(), pos.getZ(), 2.5F, Explosion.BlockInteraction.BREAK);
            }

        }

    }

 

Edited June 30, 2022 by Syric

[warjort]

Are you sure the pos is correct?

Forge has a ExplosionEvent.Detonate that will pass a list of potential entity targets.

Does your player appear in that list? You might also check some of the other data in the Explosion object passed on that event.

 

However:

There's also a piece of code in the Explosion class that looks like it checks the entity's distance to the explosion, if it is zero they are excluded from damage!

It looks like this is done to avoid a divide by zero issue?

If you are using the player's position for the explosion you might be getting caught by this? Try moving the explosion position upwards by half a block.

[warjort]

Quote

checks the entity's distance to the explosion

Actually it is with the entity's eye position.

[Syric]

I found the error. The explosions were being spawned at the block's small corner, while the block was still present. This frequently meant that the block absorbed the majority of the explosion and shielded the player from damage.