How to access ECS data from render graph nodes?

[KislyjKisel]

After extracting/preparing ECS data, what should I do to pass it to render graph node? Using &World to retrieve data is only possible when using resources or "manual" functions, but they require an entity. In sources I've found the entity was taken from an input slot connected to VIEW_ENTITY. I assume for custom entities other outputs are needed?

[djeedai]

Essentially you need to inject the data you need from the render node into the render world, one way or another, during the extract phase. That means either via a resource or via components on entities. Then you can read it back like you'd do for a normal system since the prepare and queue phases access the render world by default, not the app one. So just make a query. One subtlety here is the use of lifetimeless accessors like SQuery instead of Query but although I have an intuition about it I don't understand it enough to give a good explanation of it.