V7 - Thigh bend vs Thigh twist

Sensual Art

Thigh twist is nested under thigh bend for V7 (assuming for other G3 chars as well)

Under parameters pane : General > Transform > Rotation

For thigh bend there are three parameters - Bend, Side-side, Twist . For thigh twist there are same three parameters "mirroring" the values set in bend but listed in a different sequence i.e Twist, Side-side and Bend. I quote the mirroring because if I change the values in thigh bend the same change relects under thigh twist as well.

What is the point in having nested parts with exactly same values but displayed in different sequence in the studio? How does the sequence of setting parameters matter?

 

 

SixDs

The movements of all rigged models such as Genesis 3 Female are controlled by "bones". These bones may or may not conform to the actual bones within a human body. The two nodes that you refer to in G3F (V7 uses the same bones), Thigh Bend and Thigh Twist, refer to two separate "bones" within the model's thighs, and therefore offer the same movement options regardless of which you select. The Thigh Bend node will control all bones below it, so it will twist, bend or mone side-to-side all the lower leg, including the Thigh twist bone. Similarly, the Thigh Twist bone will move all bones below it, but it will also affect the Thigh Bend bone which is above it in the heirarchy. So the effect on the model will be the same..

Richard Haseltine

Genesis 3 uses general weightmapping, not the TriAx system used for Genesis and Genesis 2. As the name implies, the older system had a separate weight map for each axis (and for scaling and bulges) but general weightmaps use only a single map for each bone. Since the bend/side-to-side and twist need to behave differently they are split across two bones, and to make life easier for users their parameters are linked so that both can be adjusted with a single bone selection.

barbult

Aha! At last it makes some sense. Thanks, Richard.

Sensual Art

Richard Haseltine said:

Genesis 3 uses general weightmapping, not the TriAx system used for Genesis and Genesis 2. As the name implies, the older system had a separate weight map for each axis (and for scaling and bulges) but general weightmaps use only a single map for each bone. Since the bend/side-to-side and twist need to behave differently they are split across two bones, and to make life easier for users their parameters are linked so that both can be adjusted with a single bone selection.

Richard, sorry for the delayed response, but I see that bend, side-side and twist parameter combinations are pretty common across other joints as well such as pelvis, abdomen, chest, neck etc. There we are able to get the desired movements without requiring any additional bone. This additional bone is evident only in cases of thigh, shoulder and forearm nodes.

Digging a little deeper into their hidden parameters, I found a difference. The Shoulder Bend node has "X-Rotate" whereas the Shoulder Twist node has "Y-Rotate" and "Z-Rotate" parameters which are editable once unlocked. The Forearm Bend node has "X-Rotate" and "Z-Rotate" whereas the Forearm Twist has "Y-Rotate" and "Z-Rotate" parameters with the "Z-Rotate" parameter common but behaving differently in both nodes.

In case of pelvis, abdomen, chest, neck these X/Y/Z-Rotate parameters are absent.

Apparently, these X/Y/Z-Rotate parameters are not just "mirrored" parameters controlled by other parameters, but they themselves introduce new degrees of movement when used - movements that (I think) cannot be achieved via combination of bend, side-side, twist parameters.

Shouldn't the Rotate parameters be editable and the mirrored parameters (in Twist nodes) hidden by default?

Richard Haseltine

The exact roles of the different axes (two bends and a twist) will depend on the orientation of the bone. Beyond that, I'm not sure what you mean or what you want to do.