I'm talking about the preview engine - you don't move the camera in rendering :)

This is a digression from the OP's question but - as preview quality improves, memory usage is going to go up.  

Quote - I'll grant you that each node in the shader that is currently being edited is occupying memory for its little preview, but those are discarded as soon as you selected a different prop and your not in the material room. I verified that with a shader of 131 nodes in memory, they increased Poser's memory use by about 4 megs. This makes sense since each is 100 by 100 by 3 bytes for RGB times 131 = 3,930,000 bytes. When I selected another object, the memory was released.

A)  How accurate is the preview for that shader setup?  If it shows a reasonably accurate preview instead of a flat white, then that image data has to be stored somewhere in memory.  Well, it doesn't have to, but recalculating it from scratch is wasteful as long as there is sufficient available memory for the whole preview.
B)  What happens when you move the camera in the preview for that shader setup?

I understand what you're saying, that during rendering, it makes no sense to cache image data beyond what you need for the current pass.  And what I'm talking about doesn't apply too much to Poser 6 since it has a very primitive preview engine, and really not terribly much to Poser 7 either (not much better).

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