Vis (Thaumcraft 4)

Vis is the main form of energy harnessed in Thaumcraft 4. It is stored in wands (as well as scepters and staves) or Amulets of Vis Storage. It can be harnessed from mobs as small motes of light that replenish 1 point of their respective aspect or through Aura Nodes. The only vis that can be harnessed are those of the six primal aspects:, , , , , and. It is generally used for crafting items at an Arcane Worktable that require magical energy, completing some magical devices, or utilizing wand foci.

Centivis
Once enough research has been done via the Thaumonomicon, the player will be able to create Energized Nodes that can release vis in the form of centivis (CV). Vis in this form cannot be directly harnessed by wands (though Amulets of Vis Storage can be charged in this manner). Its primary purpose in this form is to power certain magical devices to start them up (e.g. Focal Manipulator) or hasten their processes (e.g. Essentia Crystallizer and Infernal Furnace). If a device is within 8 blocks of the Energized Node it is able to absorb centivis directly from the node; otherwise, Vis Relays will have to be used to connect the two.

Calculating the Centivis output and requirements
The centivis, or more properly, centivis per tick (cv/t) rating of a node is a measure of how many 1/100's of a full vis a node can transfer per tick. So, for example, if a 1 cv/t node was being used via a Vis Charge Relay to recharge a wand, it would be able to recharge 1 point of  every 5 seconds, as it would take 5 seconds to transfer 100cv at 20cv per second.

The actual centivis rating that an energized node has in each aspect is the square root of the highest source of that aspect on the original node. This is an integer value (i.e truncated, or rounded towards zero.). For a node with compound aspects, an aspect is a source of a primal if that primal is used to make that aspect or any of the aspects that it is ultimately made from. So, a 20, 10 node would be calculated as though it was a 20 , 20  node. If the node being energized is Bright, or Pale, a 20% bonus (or penalty) is applied to the source aspect total BEFORE the square root is taken.

Most devices that draw Centivis do not draw CV every tick, but they will draw a packet of the available centivis to fill an internal buffer - typically 10cv, and then draw from that internal buffer to remain in a powered state - as little as .5cv per tick - requesting cv only when the internal buffer is empty. (The example presented would only draw a 10cv packet every 20 ticks). Each time a device does draw a cv packet, the path taken will pulse with the color of the aspect drawn.