我如何获得玩家的视线

Question

Im trying to get the Line of sight of a Player and set the block at the end to ice, but whenn i get the Vector of the line of sight it Counts the air as a block and sets it to ice how can i exclude the air? (Sorry for bad english xD)

Here is my Code

Vector lineOfSight = player.getEyeLocation().getDirection().normalize();
Block block = player.getLocation().add(lineOfSight).getBlock();
block.setType(Material.BLUE_ICE);

Answer 1

I'm not sure whether or not that code is in a loop, but you could try the following:

if(!block.getType().equals(Material.AIR)) // I am not sure about the actual enum declaration of air, but your IDE will suggest it.
    block.setType(Material.BLUE_ICE);

Answer 2

Assuming that you don't want the line of sight check to run indefinitely, here's how you could do it with a maximum distance - you could change this to a while loop, but I wouldn't advise it.

Vector lineOfSight = player.getEyeLocation().getDirection().normalize();
double maxDistance = 40;
Block finalBlock = null;
for(double i = 0; i < maxDistance; ++i){
    Block block = player.getEyeLocation().add(lineOfSight.clone().multiply(i)).getBlock();
    if(!block.getType().isSolid())
        continue;
    finalBlock = block;
    break;
}
if(finalBlock != null)
    finalBlock.setType(Material.ICE);

Simply, this will iterate along the players line of sight up until the specified distance. If a solid block is found at any point, the loop breaks and the block is set to ICE . You can change the isSolid() condition to check specifically for AIR if you wish, as this will not count; for example, WATER as solid.