Topic: Hatch Pattern Not Found - How does it draw it then?

[James Cannon]

So you open a drawing from someone else.  They use a custom hatch, or a hatch that's just from some other program or vertical.

I open it on my machine without having the .pat file for that hatch.  Somehow Autocad still draws this hatch correctly.

How the heck does it draw the hatch, if I don't have the hatch pattern?  I thought it would be like having a text object with a font I don't have... it'd have to subsitute... but it doesn't- it draws the hatch properly.

That's -always- made me curious.

[Matt__W]

I've always thought of it being like a type of proxy object or an embedded shape file within the drawing.  Although I could be wrong.   

[James Cannon]

Better than what my guess was; magic compu-gnomes.

[Matt__W]

Better than what my guess was; magic compu-gnomes.

Are they related to the Travelocity gnome??   

[M-dub]

Is there an Alternate Hatch Pattern setting somewhere like there is for fonts?

If so, maybe their custom hatch pattern looks just like the one you have set as your alternate?

/stab in the dark

[James Cannon]

Nah, I don't have any custom hatches at all these days.  It's nothing I have.

[M-dub]

No, I was thinking that maybe they took one that's a standard issue hatch pattern and renamed it for whatever reason, but the one they renamed is also being used for your alternate pat... if the option to set an alternate even exists.

Still... it's just a wild guess.

[Jeff_M]

IIRC, a hatch is just a special block. When you apply a hatch it creates a block with a name you won't find in the block table, but the original hatch pattern is tied to it. When you open the drawing it looks for that pattern, if found the hatch will be drawn according to that pattern's definition. If it isn't found, then the last "block" is used.

[Matt__W]

IIRC, a hatch is just a special block.

I just pictured a hatch pattern with a helmet and racing stickers.   

[SDETERS]

Per JEff_M's Comment I wonder if you modify the Boundary of the hatch if the hatch will automatically update.  Or will it just stay Like a block and not fill the space in completely?

Make sure you try this on a copy of the drawing not the good file.

[hugha]

The hatch definition is stored in the drawing.

You can use GETPAT ( www.turvill.com ) to extract it.

Similarly, HatchKit ( www.hatchkit.com.au)  can extract it from a DXF of the drawing or a drawing portion containing the hatch.


Hugh Adamson
Cadro Pty Ltd
www.cadro.com.au