CREATE FROM CAD CROSS SECTION wrong offset?

I am in the process of modeling a FM road project for some dirt quantities. Since we don’t have much for the side slope transitions. I was going to CAD Cross Section the side slopes. First, I should have verified that the cross sections had the right elevations and they don’t. I verified after I created the slopes from CAD PDF. I was then verifying my converted 3D linestring offset from my alignment. My right side matches my offsets. The left side does not. I would have said o well, cause I can not use them since elevations are wrong. I still want to know why the linestrings are on the wrong offset.

To verify the cross section I went ahead and import a few sheets to digitize and yup, the CAD linestrings are wrong on the left side. The blue lines are the CAD and the white is the digitize lines.
ICAD PDF Cross Sections.vce (15.7 MB) deas why they are wrong?

I will take a look Frank - my guess is that the offset and elevation labels in the cad / pdf vectors are not sufficiently separated or sufficiently well defined - the error you are seeing is because it uses the values to scale and locate the data and if it gets confused it will generate wrong results.

Will.look tomorrow

It’s been awhile since I checked on this post. Any luck on finding out what happened?

I looked at the sections and here were the issues

  1. When you are working in the PDF Sections mode, you are working in Sheet View and in Sheet Units. The entry field for the Maximum Grid text distance from grid was set to 0.1’ but the text in sheet view was 0.24 or 0.445 in from the grid - so the search distance to link the Grid line to the right grid text was too great and it could associate the wrong label with the wrong grid lines - that will generate a scale error

  2. You had all the Major and Minor Grid lines visible and the fact that the minor grids were closer to the Grid Text will again cause ambiguity in the scale computations - you want to eliminate the grid lines that do not have any grid labels to eliminate the ambiguity

Sections before I changed them

Sections after I changed them

image

Once I fixed those two items, the sections flipped and scaled correctly

I added the file back here for reference

The key with getting good section flipping is to make sure that you eliminate “ambiguity” to allow the computations to run cleanly and not have any chance to get it wrong - this means eliminate duplicate data (lines and text) and eliminate unnecessary extra data (in this case the grid lines). Also be very clear of the difference between working with CAD data in Plan view where you are working in USFeet whereas in Sheet View you are working in Sheet Units i.e. Inches - so when you measure the distance of the Text from the Grid (measure it) and then enter it as 0.24in not as 0.24 which the software reads as 0.24’ which is a big distance in sheet view.

CAD PDF Cross Sections.vce (15.7 MB)

Alan

PERFECT, I was actually working on a project using this feature last week and I keep getting alot of shifting in my station cross sections. took me a few hours to realize that my MAX distance was off. Was driving me nuts, here I was moving my text, deleting lines and nothing worked. Until I told myself to change the MAX distance which was set at .10 and had to be lower to a .07.

noted on the delete grid lines with not text!!! will for sure try the MAX distance at first to.

thank you for your help and advice!!!

Good to see you persevering here Frank - you will be a Grand Master by the time we next meet!