The bug
When a weighted pressure plate initially detects an entity on top of it, it will always consistently output a power level of 1 after two game ticks. However, that is not the case if an additional mob is added that should increase the power level. In this case, there will always be a longer delay of a seemingly random amount of time.
Both light and heavy weighted pressure plates are affected. For heavy weighted pressure plates, the delay seems to be significantly longer than for light weighted pressure plates.
I discovered this attempting to use the weighted pressure plate for its intended use of detecting the number of entities in a given area, specifically I was trying to detect whether an item stream had dissimilar items in it because different items types would not stack and produce a signal strength greater than 1. However due to the random delay for consecutive items, it would often pass over the plate before it was detected making the setup effectively useless.
To reproduce
Place a weighted pressure plate and connect a line of redstone dust to it
Summon a mob on top of the pressure plate
→ ✔ Observe that the pressure plate outputs a redstone signal with a strength of 1 exactly two game ticks after the mob has been placed on the pressure plateSummon another mob
→ ❌ The delay is longer than two game ticksRepeat
→ ❌ Observe that the delay is not the same every time
Demo
Here's a test world showcasing this issue:
[media]In this video you can see that the delays for level increases are inconsistent: https://youtu.be/IEJARc78FyE
Linked issues
relates to 2
Attachments
Comments 6
can confirm in 1.18.1 however it might be intended due to the way it gets scheduled. even if its intended it is still confusing behaviour
2no2name and I looked into this behaviour and it is caused by the weighted pressure plate only checking for changes in power level every 10gt after initial activation. So the random response time is actually a consequence of a random input only being interpreted by the pressure plate on a regular, albeit long, interval. So upon placing the first entity the pressure plate will have a 2gt delay in which it will then output the power level corresponding to how many entities are on it, then it will schedule itself to check again 10gt later. This might be intended behaviour for the component, to minimise the amount of checks that it does woould technically reduce the lagginess of the component. But the weighted pressure plate is very underutilised in redstone at the moment, likely because it is so limited by this long interval between checks. Sometimes if you make a components too dumb to save on the games resources that component becomes pretty useless.
I uploaded a video with a redstone level resource pack showing how severe this delay is. The weighted pressure plates are relatively useless for dealing with entities when they will always output power level 1 before updating.
(I realize this is slightly different from the issue reported but falls under the same umbrella)
Issue existed in Bedrock too and was fixed in 1.20: MCPE-156773.
Can confirm. I've attached a test world and rewrote the ticket. If I got anything wrong, please tell me.