Using It! - Letratone!

Younger readers can Google Letratone, the rest of you may remember fiddly scalpel work and just how hard it was to pattern a drawing!

Here is a link to a cell library containing percentage dot screens that could be useful for giving a different 'old school' character to shaded areas. They will be quite efficient in 2D DGN vector graphics but will probably create massive numbers of elements if exported to other formats so use with that in mind.

Scale as required when placing, the cells are drawn at 1mm in size to make the maths easy.

  • When I was at the local DOT, I was the Project Manager on the first 100% CAD Project. The plans were done in DGN and DWG. For the DGN files we had two Vax's and about 8-10 Actem workstations and one large digitizer terminal (one color screen & one B&W screen).

    To show shading on the plans, we made shapes of all the areas for the 6 plan sheets that covered the project. We copied them all into one file and moved and rotated them until they were all lined up on top of each other and created one shape that just barely covered them.

    We then patterned that one shape with a cell we called ZIP. This took a long time, as I recall.

    By referencing that file into each sheet, rotating it as needed to cover the areas to be shaded, we were able to get the desired effect without overwhelming the system.

    In a few areas, we needed a hole in the shading. We did this by making a clipping shape that followed around the outer area and at one vertex, continued into the perimeter of the "hole", tracing around that perimeter and then followed back out along the same line, to the outer element to eventually close the shape. We had plotting software that could plot irregular clip boundaries, even though on screen, the clip boundaries showed up like range blocks.