The relax modifier changes the apparent surface tension in a mesh by moving vertices closer to, or away from, their neighbors. The typical result is that, the object gets smoother and a little smaller as the vertices move towards an average center point. You can see the most pronounced effects on objects with sharp corners and edges.
Step1: Create a plane.
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Step2: Convert plan to editable poly by right clicking on the plan.
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Step3: click on the vertex option of editable poly. Then select two vertex of plan.
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Step4: Right click on the move tool. Then specify distance of Z-axis.
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Step5: Select all the vertex then click on modify tab and select relax tool.
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Step6: First uncheck keep boundary pts fixed option and specify parameters.
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