[1.15.2] How is blindness processed?

[Novârch]

I'm trying to make a potion effect that combines a few vanilla potion effects, the purpose being being able to easily remove it without removing effects the player might have had prior to getting it, one of these effects is blindness. How does the blindness effect work? Does the game check whether you have it while rendering, can I replicate it's functionality with an event?

[imacatlolol]

The effect is controlled by FogRenderer#updateFogColor, and FogRenderer#setupFog. Look for the usages of Effects.BLINDNESS to see the exact math it performs.

Hook on to the EntityViewRenderEvent$FogDensity and EntityViewRenderEvent$FogColors events to override the vanilla behavior and do your own logic (the former event will need to be canceled for your stuff to work).

I recommend using a lower event priority and then checking the state of the events so that other mods can override your system if desired.

[Novârch]

1 hour ago, imacatlolol said:

The effect is controlled by FogRenderer#updateFogColor, and FogRenderer#setupFog. Look for the usages of Effects.BLINDNESS to see the exact math it performs.

Hook on to the EntityViewRenderEvent$FogDensity and EntityViewRenderEvent$FogColors events to override the vanilla behavior and do your own logic (the former event will need to be canceled for your stuff to work).

I recommend using a lower event priority and then checking the state of the events so that other mods can override your system if desired.

Thanks for the help! Everything works fine except this line, and it seems that it's pretty important because nothing renders when I remove it.

[Draco18s]

That lets other mods be notified about fog and change it if they want.

[Novârch]

1 minute ago, Draco18s said:

That lets other mods be notified about fog and change it if they want.

Than I must've goofed something else up, but I don't know what because I just copied the vanilla FogRenderer code.

[imacatlolol]

1 hour ago, Novârch said:

I just copied the vanilla FogRenderer code.

There's your problem.

The event is normally intended to be used by simply setting the fog density via the event's setDensity method. The same goes for the fog color.

A density of 0.3 will produce a very similar effect as the vanilla method, but it's not perfectly identical since vanilla uses more complex methods. However, the difference is very subtle and none of your users will likely even notice.

If you really want an identical effect, you should set the density to 0 and then use those four RenderSystem method calls towards the end.

Edited May 14, 2020 by imacatlolol
Slightly better wording

[Novârch]

9 hours ago, imacatlolol said:

There's your problem.

The event is normally intended to be used by simply setting the fog density via the event's setDensity method. The same goes for the fog color.

A density of 0.3 will produce a very similar effect as the vanilla method, but it's not perfectly identical since vanilla uses more complex methods. However, the difference is very subtle and none of your users will likely even notice.

If you really want an identical effect, you should set the density to 0 and then use those four RenderSystem method calls towards the end.

Thanks for the help, gotten the exact effect I was looking for!