Light level differences between client and server?

[JayWolves]

Hello everyone,

I'm kinda new here, I read a lot of topics for reference and if I had issues, but now I really got stuck here so I have to ask for myself.

 

I looked up my issue here in the forums and on Google but all topics I found where either not about my problem in particular or have not been answered in at least 2 years.

 

So here am I:

 

I try to figure out the light level above my block, taking into account whether it can see the sky or not. Works out fine so far, but when it came to the point where I implemented particle effects, I noticed that even though its night it generates particles as it was day. So I debugged it (simply System.out.println) and found something very irritating:

 

[server thread/INFO] [sTDOUT]: [...]: getBlockLightLevel: 4

[server thread/INFO] [sTDOUT]: [...]: getBlockLightLevelSaved: 0 (with Enum Block)

[server thread/INFO] [sTDOUT]: [...]: getBlockLightLevelSaved: 15 (with Enum Sky)

[server thread/INFO] [sTDOUT]: [...]: SkyLightSubstract: 11

 

[Client thread/INFO] [sTDOUT]: [...]: getBlockLightLevel: 15

[Client thread/INFO] [sTDOUT]: [...]: getBlockLightLevelSaved: 0 (with Enum Block)

[Client thread/INFO] [sTDOUT]: [...]: getBlockLightLevelSaved: 15 (with Enum Sky)

[Client thread/INFO] [sTDOUT]: [...]: SkyLightSubstract: 0

 

Why is there any difference between the client and server side light levels? What am I missing?

 

Hope somebody can point me to the right path.. =)

 

Greets,

Jay

[jeffryfisher]

I think there's another function for combined light level. Would that save you from calculations? Or, if you care more about night/day rather than actual light-level (which can be affected by weather, trees etc), skip all light-level calc and go straight for modulus (%) of time.

 

I'm unsure why the client/server numbers are incongruous. Do you have enough context (e.g. world-time) to be sure the numbers are comparable?

[JayWolves]

Well, I did not found another function for a combined value, but I figured out that for my case, a combination of calculateSkylightSubtracted(), getSavedLightValue() and canBlockSeeTheSky() work fine. Here's my code:

 

int lightLevel = 0;

	if (canSeeSky()) {
		int lightLevelSky = worldObj.getSavedLightValue(EnumSkyBlock.Sky, xCoord, yCoord + 1, zCoord);
		int skyLightSub = worldObj.calculateSkylightSubtracted(0f);

		int lightLevelBlock = worldObj.getSavedLightValue(EnumSkyBlock.Block, xCoord, yCoord + 1, zCoord);

		if ((lightLevelSky - skyLightSub) < lightLevelBlock)
			lightLevel = lightLevelBlock;
		else
			lightLevel = lightLevelSky - skyLightSub;
	} else {
		lightLevel = worldObj.getBlockLightValue(xCoord, yCoord + 1, zCoord);
	}

 

This estimates the exact light level "on" (above) my block. IF someone can find a better/simpler solution I would be happy, but this will work for now =)

[jeffryfisher]

If your only purpose is to generate a visual effect like particles (ooh, pretty), then the server does not even need to do the calculation.

 

As for combined light level:

 

public interface IBlockAccess {

    <snip>

    @SideOnly(Side.CLIENT)
    int getCombinedLight(BlockPos pos, int p_175626_2_);

 

Class world implements this interface, so your worldObj probably offers it, but only on the client side where you probably need it.

 

BTW, There's also an "isDaytime()" method based on light that can actually return false during a heavy thunderstorm (that's when I turned to modulus of time rather than relying on light).

[JayWolves]

That is quite helpful, wasn't aware of that method.

 

In my case, I need the lightlevel on both sides:

Client -> create partikels based on lightlevel (more light, more fancy particles )

Server -> calculation some processing based on the lightlevel

 

But I'll try out your idea, at least it will make the client part shorter =)