Make a block only collidable for a specific entity

[MosquitoFRA]

Hello everyone. Here is my issue: I don't know how to make a bloc only collidable for players. Arrows can cross it which is very annoying because I want to make a shield which stop projectiles and not players. Any help would be great.

[diesieben07]

Override Block#addCollisionBoxToList to create a different bounding box based on the entity type being passed in.

[MosquitoFRA]

Do you mean like this?

@Override
public void addCollisionBoxTo List(IBlockState state, World world, BlockPos pos, entity.projectiles)

[diesieben07]

That is not valid Java. So no.

[MosquitoFRA]

In fact, I'm not used to this method. I found an example:

public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, @Nullable Entity entityIn) {
        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, under);

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, middle);

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, top);
    }

 

So what do I have to do with these information?

[diesieben07]

See that parameter of type Entity? Check what type of entity it is and apply a different bounding box based on that information.

[MosquitoFRA]

I replace "entityIn" by "tileEntity" or "entityProjectiles"?

[diesieben07]

4 minutes ago, MosquitoFRA said:

I replace "entityIn" by "tileEntity" or "entityProjectiles"?

I don't know what you mean by that. But probably no. You need an if statement.

[MosquitoFRA]

public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, @Nullable Entity entityIn) 

 

     if(entity.projectiles)
    

Edited November 3, 2018 by MosquitoFRA

[diesieben07]

What are you trying to tell us?

[MosquitoFRA]

Sorry, I was editing. I don't know why there is @Nullable Entity entityIn?

[diesieben07]

It's giving you the entity that is colliding with your block.

[MosquitoFRA]

public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, @Nullable Entity entityIn)

     if(entity.projectiles)

    {   super.addCollisionBoxToList(pos, entityBox, collidingBoxes, under);

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, middle);

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, top);
    }

Is it like this?

[diesieben07]

That does not even compile, your method body is missing the curly braces.

entity is also not a local variable, field or anything else. Assuming you meant entityIn, you would need a null check before accessing any fields or methods on it. Assuming you added that, projectiles is still not a field that exists on the Entity class.

 

So, no, nothing about what you posted makes sense.

[MosquitoFRA]

For the entity, it's entityLiving (I think it's for projectiles).
And I don't know to do this null check

     { if(EntityLiving)

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, under);

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, middle);

        super.addCollisionBoxToList(pos, entityBox, collidingBoxes, top);
    }

 

Edited November 4, 2018 by MosquitoFRA

[diesieben07]

Your code does not make any sense.

Please learn basic Java before making a mod.

[MosquitoFRA]

Could you correct it, please ... I didn't find an answer anywhere on google and i tried javadoc but didn't know where to go to find the good method.

[MosquitoFRA]

I have to leave. Thank you for your help and patience.

[JimiIT92]

What diesieben was trying to say is that you should learn how to check if an entity is of a given instance or has some particular properties defined in the entity class. I'm pretty sure that the entity class itself has no "projectiles" property, and even if it does i don't think it's a boolean by the name. That being said, you should do something like this (assuming you are using Forge 1.12.2)

 

@Override
public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, Entity entityIn, boolean isActualState) {
  if(entityIn instanceof EntityPlayer) {
    // Do stuff
  }
}

 

In this case you check if the entity that collides with the block is a player. If so then you can do whatever you want (like adding the collision box). 

[Daeruin]

@MosquitoFRA there are hundreds of resources to help you learn basic Java online. I started with Codecademy. Please run through some basic Java tutorials or courses before you keep trying to make mods. You are setting yourself up for constant frustration and failure until you learn more Java.

[MosquitoFRA]

Huge thanks @JimiIT92. I will try.
And finally decided to look at some videos.

[larsgerrits]

On 11/4/2018 at 5:29 PM, JimiIT92 said:

...

@Override
public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, Entity entityIn, boolean isActualState) {
  if(entityIn instanceof EntityPlayer) {
    // Do stuff
  }
}

...

And now you've just give him the code which he can copy-paste without learning anything from it.

[MosquitoFRA]

@Override
          public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, Entity entityIn, boolean isActualState) {
               if(entityIn instanceof EntityPlayer) {
                         public AxisAlignedBB getBoundingBox(IBlockState state, IBlockAccess source, BlockPos pos) {
               return new AxisAlignedBB(0.0D, 0.0D, 0.0D, 1.0D, 1.0D, 1.0D);
                    }
               }
          }

I have this but it doesn't work

Edited November 5, 2018 by MosquitoFRA

[Cadiboo]

Learn java. Just the basics, 5 minutes of learning java and you will understand how horribly wrong that is on every level

[MosquitoFRA]

@Override
          public void addCollisionBoxToList(IBlockState state, World worldIn, BlockPos pos, AxisAlignedBB entityBox, List<AxisAlignedBB> collidingBoxes, Entity entityIn, boolean isActualState) {
               if(entityIn instanceof EntityPlayer) {
                         getBoundingBox(IBlockState state, IBlockAccess source, BlockPos pos) {
               return new AxisAlignedBB(0.0D, 0.0D, 0.0D, 1.0D, 1.0D, 1.0D);
                    }
               }
          }

I tried this but it didn't work