[1.15.2] attackEntityFrom always returning false

[byalexeykh]

Code: 

TraceResult = mc.objectMouseOver;
                if(TraceResult!=null){
                    if(TraceResult.getType() == RayTraceResult.Type.ENTITY) {
                        EntityRayTraceResult EntityTrace = (EntityRayTraceResult) TraceResult;
                        if (EntityTrace.getEntity() instanceof LivingEntity) {
                            if (EntityTrace.getEntity().attackEntityFrom(DamageSource.causePlayerDamage(mc.player), 3)) {
                                System.out.println("Attack successful");
                            }
                            else{
                                System.out.println("Attack failed");
                            }
                        }
                    }
                }

What am I trying to achieve:

Damage entity when player releases left mouse button.

Input tracking works well, but the problem is:

After I release the left mouse button attackEntityFrom always returns false.

Aditional info:

These "if's" are located in ClientTickEvent event.

Edited June 13, 2020 by byalexeykh

[DavidM]

16 minutes ago, byalexeykh said:

EntityTrace.getEntity().attackEntityFrom(DamageSource.causePlayerDamage(mc.player), 3)

You cannot do that on the client side. That method should be called on the server side.

You should do the ray tracing on the server side (there might be a slight difference in player's facing with the client though).