In my mod I intend to have several potions that alter the way entities are rendered when active.  The issue I have is that at the moment the rendering changes only take place if the player is the entity under the effect of the potion.  If another player, or any other entity is under the effects they are rendered as they normally would be. I know that the problem is that the client doesn't "know" that other entities are under the effect of a potion. But I'm not sure how to solve this.  I assume I need to send a packet but I'm a little reluctant to do anything that involves sending a packet every tick and anyway I not quite sure what info to send. It isn't as though I can send the entity object in the packet and i'm not sure how I would get a hold of the specific entity object on the client to set it to having an active potion effect. 

For reference this is my code for altering an effected entity's rendering:

	@SubscribeEvent
	public void onRenderLiving(RenderLivingEvent.Pre<EntityLiving> event)
	{
		if(event.getEntity().isPotionActive(DemEffects.SHRINK))
		{
			GL11.glPushMatrix();
			GL11.glTranslated(event.getX(), event.getY(), event.getZ());
			GL11.glScalef(0.4f, 0.4f, 0.4f);
			GL11.glTranslated(-event.getX(), -event.getY(), -event.getZ());
		}
	}
	
	@SubscribeEvent
	public void onRenderLiving(RenderLivingEvent.Post<EntityLiving> event)
	{
		if(event.getEntity().isPotionActive(DemEffects.SHRINK))
		{
			GL11.glPopMatrix();
		}
	}

 

Edited February 1, 20187 yr by Codasylph

You can send the entity's UUID in the packet. 

 

You should look at how the packets that get entities to emit particles when under potion effect work. Like you said it isn't a good idea to send packet every tick so probably send once when effect starts and then either has timer or stops when a follow-up packet is sent to indicate potion has worn off. 

8 hours ago, jabelar said:

You can send the entity's UUID in the packet. 

I can't believe I didn't think of that.  Thank you

8 hours ago, jabelar said:

You should look at how the packets that get entities to emit particles when under potion effect work. 

I actually looked at that first, but it basically just sends a packet to clients tracking the entity to say "spawn particles here." The client still doesn't "know" that the entity is having particles spawned because of an effect, just to spawn them and nothing about what was already being rendered is changed so that didn't really help me.

 

8 hours ago, diesieben07 said:

This is what the entity ID(Entity::getEntityId, World::getEntityByID) is for, actually.

 

As for the packets, you need to send one to all players tracking the entity with the potion (EntityTracker::getTrackingPlayers) when the effect starts and stops, you can use Potion::applyAttributesModifiersToEntity resp. Potion::removeAttributesModifiersFromEntity for this.

You also need to send a packet when the entity already has the potion and a new player comes into tracking range, you can use PlayerEvent.StartTracking for that.

This helps! Thanks a bunch!!