topic Trying to hatch a complex object - AutoCAD 2025 in AutoCAD Forum

Trying to hatch a complex object - AutoCAD 2025

d_pencik — Tue, 09 Sep 2025 17:47:41 GMT

Hello, i have a complex object, that i Want to hatch to make it not transparent (when placing in 2D view in front of another object). I tried to make boundary of the block with no luck. Then i tried to select all parts of the complex object to hatch it also with no luck. Please help.

@d_pencik Your post title was modified to add the product name and version and to increase findability - CGBenner

Re: Trying to hatch a complex object

pendean — Tue, 09 Sep 2025 12:40:00 GMT

@d_pencik So where do you want to hatch exactly? Hard to tell in your 47,857 2D objects of lines and arcs what it is you are trying to do, which is likely your issue, these are very fragmented

But if you just zoom in to the area you want to hatch, and if needed, hide whatever else is not needed, you can indeed hatch all you want (and make it transparent etc).

Re: Trying to hatch a complex object

d_pencik — Tue, 09 Sep 2025 12:54:54 GMT

Hello, i want to hatch the entire object, so i can give it a colour and place it in front of other objects.

Re: Trying to hatch a complex object

paullimapa — Tue, 09 Sep 2025 16:08:28 GMT

which parts of this drawing should be the boundary that you want to apply the hatch?

Re: Trying to hatch a complex object

d_pencik — Tue, 09 Sep 2025 16:15:36 GMT

Just the outline

Re: Trying to hatch a complex object

R_Tweed — Tue, 09 Sep 2025 17:18:42 GMT

Disregard for previous post, for some unknown reason, I thought I was in the aca forum.

Using plain Autocad, You could create multiple boundaries of small sections and then merge them into one region to create a hatchable mask or just rough out an outline of the object with a polyline and hatch.

Re: Trying to hatch a complex object

Kent1Cooper — Tue, 09 Sep 2025 18:51:22 GMT

The "usual" way to do something like this would be to draw a closed shape outboard of and around stuff [a circle, rectangle, whatever], start BPOLY / BOUNDARY and pick in the space outside your stuff but inside the surrounding closed shape. If your stuff forms a closed perimeter, that should create a Polyline or Region outline around your stuff [and also another coinciding with the surrounding shape -- you can delete those two]. You can then use that Boundary object as you wish.

[In your drawing, even trying this around the smallest assembly, I got a dire warning about how many objects there are, and that it could take a while if I chose to proceed. I did -- it's working on it now -- we'll see whether it can get there.]

EDIT: After about two hours, it still couldn't determine a closed boundary. Problem areas circled in red:

Re: Trying to hatch a complex object

pendean — Tue, 09 Sep 2025 18:43:47 GMT

@R_Tweed wrote:
Disregard for previous post, for some unknown reason, I thought I was in the aca forum....

Is there a solution unique to ACA? Please share.

Re: Trying to hatch a complex object

R_Tweed — Tue, 09 Sep 2025 21:54:02 GMT

The tools available in ACA are different and I'm not completely sure some are not available in Autocad.

It might be good idea to explain some of the commands available with differences noted.

1. Shrinkwrap can help in some instances where it creates a polyline boundary around a selection set. Similar to the boundary command with less steps.

2. Aecpolygons allow for boolean operations and can be grip edited like polygons or hatches. It would be similar to a region that was strectchable.

3. Aecpolygons can mask. Similar to using wipeout. Except that wipeouts do not support curved segments.

4. Aecpolygons are style based, can mask and/or have a color toned "hatch" combined depending on display options.

5. AEC modify functions, subtract, divide, trim, and merge objects..

My initial response was to use an Aecpolygon as a mask.

I made an aecpolygon rectangle, used lineworksubtract command to cutout some portions, converted a few segments to arcs and used shrinkwrap to create a couple of sections, merged all into one boundary to get the shape shown.

Re: Trying to hatch a complex object

pendean — Wed, 10 Sep 2025 12:56:45 GMT

Thanks @R_Tweed Looks like they are too complex

Re: Trying to hatch a complex object

R_Tweed — Wed, 10 Sep 2025 16:15:06 GMT

@pendean

Yes, taken as a whole, shrinkwrap can be temperamental with large numbers of items, reversing curves etc. It works better with smaller sections.

This video has a few stumbles and shows that not everything works perfectly.

(view in My Videos)