Jump to content

Problem drawing polylines

Recommended Posts

An example:I have say a square and a circle intersecting. And I want to draw a polyline around the total perimeter I have a problem.No problem doing the straight edges but I am unable to continue the polyline around the curved side. When I use the cubic vertex mode it doesn’t follow the line of the curve. And sometimes when I am using the corner vertex mode it draws a curve when I want a straight line, for no apparent reason.

I know I could draw shapes and use the “add surface command” to achieve the same result, but this is impractical in some situations.

Please help as it is driving me insane!!

Link to comment

Unwanted bezier curves? Like a drunk person who thinks the entire world is spinning, VW thinks that your hand is moving at the time you click. Dragging a bit while you click (even during corner vertex creation) will automatically create a bezier point. An acquired subconscious micro-pause gives VW time to catch up. Or the computer. Whatever. You'll get consistent corners then.

The cubic polynomial curve is not a circular arc, so the curve you make will not follow the circle exactly. You have two options:1) With corner vertices at the intersections of the circle, make a new vertex between them of type 'arc' (fillet), then drag the vertex to the centre of your circle to suit. However, this works for subtended angles of less than 180.2) With corner vertices at the intersections of the circle, slap in some beziers. The exact next step or two depend on your case, but to understand what's happening, do the following.Draw a circle. Draw a regular hexagon w/ same centre, with faces touching the circle. Draw a polyline using beziers, snapping to the hexagon's corners. ( or just convert all the hexagon's corners to bezier points). The result is a simulated circle, essentially what VW does with Add Surface.

Link to comment

Matthew, while you are suggesting easy ways of drawing...

Is there a way of drawing an arc with a defined arc length? I cannot find any tools to be able to do this.

The arc length is shown on the OI palette but it is not editable.


Link to comment

Hmm, this sounds like a perfect application for the Arc tool in "Arc by 3 Points" mode in conjunction with some straight lines (or polylines).

Draw the straight bits, then use the Arc tool to snap to the line endpoints and a point on the circle. Select the 3 objects and use the "Compose" command from the tool menu.

Matthew GiampapaNNA Technical Support

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...