Can I directly sculpt the deformed actor and Poser makes a reverse calculation to create the weight map as necessary or is it only possible to do it the "forward" way, by painting the map and seeing the effect?

If I'm understanding your question correctly, the answer is Yes. If you bend a limb you can create the weight map while the limb is bent. Its effect will be phased out to zero as the limb rotates to the default.

Good job on MorphLoader by the way. It is working perfectly.

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