Hatch patterns explained

[Cris-Ideas]

In this post you will fine explanation how hatches in inventor work

Hi,

I had a problem with hatch orientation, hatch scale, hatching by material and a bunch of other details. I managed to find some information here and there but for some questions I was not able to get answer even from customer support. So I had to find those my self.

Now I wish to share this knowledge with anyone who may need it. In this post I give a compressive description on how hatches are handled in inventor.

So to the point.

1) To understand fully how hatch works we first need to understand what hatch is and how it is defined.

• So hatch is basically a set of lines or line families organised in patterns that is repeated until it fills given area.
• Each hatch pattern is defined in a hatch pattern file *.pat.
• Default files are located in inventor default directory, you can find in by doing simple search on your drive.
• Your custom hatch patterns can be stored anywhere you like.
• More than one Default hatch pattern can be defined in a single .pat file.
• In one custom .pat file there can be only ONE custom hatch pattern defined.

Hatch pattern definition

  Hatch pattern consists of any number of lines (dashed, dotted, continuous) aligned in relation to each other. Basic knowledge about its definition you will find here: "hatch pattern definition".

There are however additional information not given there but very important for a user. So please also note:

• Hatch patterns used in inventor are assumed in inches (imperial units). So for all mm users, you must define hatch patterns in inches rather than in mm.
• What is also important to know is hatch pattern angle defined in hatch pattern file. If you intend to use your hatch for a material based hatching this is the angle that will be used when hatches will be created automatically*

* - this angle is influenced by "Section hatch angle" setting defined in Standard defaults. more detail description further in this post.

2) How inventor uses hatch patterns

Well inventor can use hatch patterns (defined in .pat files) in two ways.

1 method - in Standard you use there are Hatch Styles (by default there is one, but you can create more). This Hatch Style is used for section and other hatches created on drawings.

Witch of avalilable Hatch Styles is used is defined in Objects Defaults of currently used Standard.

2 method - in your Standard you can select to use material based hatching using Material Hatch Patterns Defaults settings in your Standard Default Settings.

3 method  combination of 1 and 2 method

3) Hatch pattern orientation on drawing

When hatch is automatically placed on drawing, for example when section of a part is done, orientation of a hatch pattern for a given region is result of few angles that are added.

Formulas for final angel of a hatch pattern in given area of a drawing are different for hatches applied generally (1 method) and hatches applied by material (2 method). This can lead to really big confusion.

So what factors are playing role:

Ahp - angle defined in hatch pattern file .pat. 

           45 deg in this case is only an example, angles for different hatch pattern definitions will vary.

Ahs - angle of Hatch Style defined in standard

          Please note that changes made in this field will not cause thumbnail on the right to change. This is not a preview of actual resulting hatch pattern. This can be very misleading.

Sha - Section Hatch Angle from your Standadr Default settings

        

So when hatches are created on drawings resulting angles (Ar) of hatch patterns are as follows:

for 1 method Ar = Ahp + Ahs + Sha

for 2 method Ar = Ahp + Sha

As you can see this are different.

So if you want same hatch apttern applied as material based hatch and standard hatch look the same you MUST always use Ahs =0 like so:

4) Hatch patters scale

Scaling hatch patterns is only possible for standard hatches applied with 1 method.

It is not possible to apply any scaling for hatch patterns used in material based hatches.

5) Other useful hints

• If you want all hatches on drawing to be aligned in the same direction you mus have only ONE angle defined in Section Hatch Angles in your Standard Defaults.

• If you delete all Section Hatch Angles inventor will automatically create one that will be 45 deg. So always have one defined.

• Changes made to standard defaults, hatch styles or other do not affect hatches that are already on drawing.

• Do not believe thumbnails of hatch patterns displayed in dialog widows. Always take extra caution.

Should you have anything to add, please feel free to do so.

Hope you found this post useful.

Cris.

[swalton]

Cris,

Very nice post.  Autodesk's Inventor help files should follow this style. 

[Curtis_Waguespack]

Hi Cris,

You might consider adding this to the Autodesk Knowledge Network.

Here's the link to create a new knowledge network article:

https://knowledge.autodesk.com/community/article/new

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

[PaulMunford]

Great job 🙂

[Paul-Mason]

From a quick saerch of my macine I foud these .pat files

the one's with ISO files are metric therefore BOTH metric and imperial hatching are available all depends of which file you load your hatch patterns from.

[Cris-Ideas]

@Paul-Mason

Hi,

That's strange.

I know that in other Autodesk software, Revit for example, hatches can be defined as metric or imperial and there are also other options.

But I was not able to force inventor to use my hatch pattern as metric.

Also Customer support was not helpful to explain this.

Could you try to verify how to define metric hatch to be used in inventor?

Cris.

[Paul-Mason]

This is how I cahnged from Imprial to metric, and vis-a-versa, don't know if its the correct way but it works

On clicking OK this pops-up

for all those hatch patterns already loaded but as they are being replaced by either/or the metric or imperial then you need to YES numerious times.

[Cris-Ideas]

Hi,

indeed, I looked in to .pat files and ISO are defined in mm.

But do those look OK after you load them to be used?

in .pat file there is no indication about units of  the pattern definition, so what is inside .pat file is only numbers. When I tried to use my custom hatch Inventor was using it as it was defined in inches.

so when I was using value of 1 for spacing between lines it was read as 1 inch.

Cris.

[Paul-Mason]

They seem OK, some time 45deg is actually horizontal but other than that, the scale and patterns work fine

[Cris-Ideas]

Hi,

I have tried to use hatches from acad.pat and acadiso.pat that are in inventor public documents.

But they do not work the same. those defined in mm are exactly 25,4 times bigger than those defined in inches.

Also I have discovered that hatches that are pre loaded in default DIN standard are not loaded from any of those files. (Names are different) Those that are pre loaded do have a space between ANSI and nuber and those defined in mentioned files do not.

I do not know yet where default hatches of inventor come from but maybe I will find that out.

Cris.

[Cris-Ideas]

Hi,

I have checked all .pat files that ware find on my computer.

Definition for hatches that are in default drawing templates that come with inventor are no defined in any of those files.

So question is: Where does inventor gets definitions for hatch patterns that are by default defined in default drawing templates?

Cris.

[-niels-]

Only skimmed this topic, but maybe:
C:\Users\Public\Documents\Autodesk\Inventor 2016\Design Data\Hatch.xml

??

[Cris-Ideas]

@-niels-

Hi,

thank for the tip.

There is something, but definitely not all.

There are only 3 in my case. And inside default idw there is much more. So there must be something else behind this.

Cris.

[cvbt-thailand]

I had a little trouble with this so I thought I'd document it.

In the Style and Standard Editor, after matching a Hatch Pattern to a Material Name, clicking on Save saves that definition locally (to the document). For it to be accessible for use in other documents save it to the Style Library.

In the Style and Standard Editor Dialog Box, in the Window Title Bar there is a note in parenthesis telling whether the Library is open Read Only or Read/Write. It needs to be open Read/Write.

Open the Style Library Read/Write in the Project dialog box:

First close all documents.

Open the Project Dialog Box: Click on the Big I (in the upper left-hand corner of the window) >Manage>Projects

In the lower pane, right-click on Use Style Library>select Yes

Click Save and Done.

Reopen your drawing.

Once you've matched your Hatch Patterns to Material Names and saved them (locally) in the Style and Standard Editor, close it.

On the ribbon>Manage tab>Styles and Standards panel>click Save Styles to Style Library.

The Save Styles to Style Library dialog box will open.

In the Save to Library? column, click No on the line your document is on; it will turn into Yes.

Click OK.

An overwrite update warning will appear; click Yes.

     Now your matching material hatch patterns will be assigned to section views which have Pattern - By Material assigned (the default can be changed by right-clicking on the hatch pattern in the section view and selecting Pattern[not Edit Hatch Style]). Any existing drawings can be updated in those drawings by ribbon>Manage tab>Styles and Standards panel>click Update Styles.

[kresh.bell]

Hi,

is it possible to adjust the hatch so that it is always perpendicular to the long side?

[johnsonshiue]

Hi! I could be wrong but I don't think it is doable. I guess you may want to try changing the preset hatch angle. Go to Manage -> Styles and Standards -> Styles Editor -> select the active standard -> General -> Preset Values -> Section Hatch Angles -> remove the unwanted values.

Many thanks!