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- Three points XZ: Enter three points that corresponds to the origin, the X-direction and the Z-direction. The origin and the last introduced point defines define the Z-axis, whereas the second point indicates the side of the x-z plane where the point lies.
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Local axes assigned on lines
The model has been created related to a global axes axis system XYZ that is unique for the entire problem. The main property of this system is that the local X’ axe must have the same direction than the line.
The ways for defining local axes systems are:
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Local axes assigned on surfaces
The model is created related to a global axes axis system XYZ that is unique for the entire problem. The main property of this local axes axis system is that the local Z’ axe must have the same direction than the normal of the element. 
The ways for defining local axes systems are:
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- If not, X’ axe will be in the direction of the cross product of V and N (VxN).
- Y’ axe will be the cross product of Z’ axe and X’ axe.
Intuitively, this local axes axis system is calculated so as if element is approximately contained in the plane XY, local X’ axe will point towards global X axe. If not, this X’ axe is obtained as orthogonal to global Z axe and local Z’ axe.
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