Process when Blend is 0.0

Nodes have this parameter "Process when Blend is 0.0" What is it and how does it work?

When the Blend value of a node is set to 0 then that node would normally have no effect on the composition. As I understand it, to improve performance, the default behaviour is therefore to not process any such node. But if, for some reason, you want the node to always be processed anyway, regardless of it's Blend value, then you can enable this setting.
Hope it helps
Andy

When the Blend value of a node is set to 0 then that node would normally have no effect on the composition. As I understand it, to improve performance, the default behaviour is therefore to not process any such node. But if, for some reason, you want the node to always be processed anyway, regardless of it's Blend value, then you can enable this setting.
Hope it helps
Andy

Thanks, but it doesn't really work that way, I add a few nodes for example 10 pieces and performance is lost, starts lagging. Although, as I understand it, it should miss the signal like PipeRouter does.

But if, for some reason, you want the node to always be processed anyway, regardless of it's Blend value, then you can enable this setting.
Hope it helps
Andy

What would be the reason to process with zero effect on image?

I guess it can be important if you perform some operation in the Frame Render Script field. Like copying the rendered frame (on disk) somewhere.

This is what the manual says

This checkbox forces the node to process even when the input value is zero and the image output is
identical to the image input. This can be useful on certain nodes or third-party plug-ins that store
values from one frame to the next. If this checkbox is disabled on nodes that operate in this manner,
the node will skip being processed when the Blend is set to 0, producing incorrect results on
subsequent frames

This is what the manual says

This checkbox forces the node to process even when the input value is zero and the image output is
identical to the image input. This can be useful on certain nodes or third-party plug-ins that store
values from one frame to the next. If this checkbox is disabled on nodes that operate in this manner,
the node will skip being processed when the Blend is set to 0, producing incorrect results on
subsequent frames

Oooh, now I understand. By the way, it is a pity that there is no such parameter in the nodes that would allow the signal to pass through itself at Blend=0 without loss of performance.