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How to copy and rotate a shape with special angle like 30 degree in skill coding?

richardyuan

Hello, 

I failed to search the manual and the forum to find a way to copy and rotate a shape I created with any agle like 15, 30, 45 etc.

I noticed some posts said that rotate with any angle may raise lithography issues. But in MEMS application, it's very popular to use all kinds of "strange" shapes. As the line/space is over 1um, the litho problem can be neglected. Then, what can I do in skill code?

 Thanks. 

Parents

  • Your code has two sources of rounding errors.

    The first is that you compute the angle as 360/SETS. Since SETS is an integer, and 360 is a literal integer, this is an integer division. So if SETS is 19, this ends up with an angle of 18 rather than 18.94. If you change the expression to 360.0/SETS then this will eliminate this source of rounding error.

    The second (much smaller) source is that each time it does a transform cellview, copies the figure and then transforms again. At each transform there will be a small rounding error of each point in the transformed shape to snap it to the database units used because of the resolution of the database. Because you are doing a series of transformations, each starting from the result of the previous transformation, these small errors will accumulate. They may be small enough that you can ignore, but the approach I showed was to transform from the original shape each time and vary the angle each time (so the first rotates by angle, second by 2*angle and so on) and so the small rounding errors would not accumulate.

    Kind Regards,

    Andrew 

Reply

  • Your code has two sources of rounding errors.

    The first is that you compute the angle as 360/SETS. Since SETS is an integer, and 360 is a literal integer, this is an integer division. So if SETS is 19, this ends up with an angle of 18 rather than 18.94. If you change the expression to 360.0/SETS then this will eliminate this source of rounding error.

    The second (much smaller) source is that each time it does a transform cellview, copies the figure and then transforms again. At each transform there will be a small rounding error of each point in the transformed shape to snap it to the database units used because of the resolution of the database. Because you are doing a series of transformations, each starting from the result of the previous transformation, these small errors will accumulate. They may be small enough that you can ignore, but the approach I showed was to transform from the original shape each time and vary the angle each time (so the first rotates by angle, second by 2*angle and so on) and so the small rounding errors would not accumulate.

    Kind Regards,

    Andrew 

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