- This page is about Vis Relay from Thaumcraft 4. For other uses, see Vis Relay.
The Vis Relay is a transparent block added by Thaumcraft 4. It is used to extend centivis (CV) paths from another relay or an Energized Node to another relay or CV-using device. Its maximum range is 8 blocks. Relays can be attuned to a certain color to prevent the relay from transferring over to an undesired one. Attune them by right-clicking on the relay with an aspect shard of the desired color, or cycling through all possible colors by right-clicking with a wand in hand.
Relays can only accept CV from one source, though it can output to multiple Relays.
— Thaumonomicon (truncated)
Energized nodes no longer store or recharge vis, nor can vis be drawn from them with a wand or other means. Instead they produce a steady supply of CV (centi-vis, or a hundredth of a vis) each tick. This energy can be tapped by placing vis relays near the energized node.
Each relay acts as a conduit for CV and any number of relays can be placed within 8 blocks of an energized node. Relays also transfer energy to each other allowing you to create a network that transports vis to anything that needs it, like the Infernal Furnace.
Relays use a branching system, so each relay can have only one source (either another relay, or an energized node), but may have multiple child relays that branch off it.
You can also 'tune' a relay to one of the primal aspects by using an appropriate vis shard on it. Clicking on it with a wand will also cycle through the possible attunements. This does not limit what vis can flow through that relay, but does prevent it from connecting to any other relay except untuned ones or ones tuned to the same primal.