Access is Denied - for editing "VEXpressions.txt"

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1101 posts
Joined: Sept. 2015
Hello, I know I can simply save a vex preset with the gear icon.

But if I can get a preset to show up in the drop-down menu to the right of the code window - well it would be a little faster accessing them >.<

Saw a source recently on how to do this, but I forgot to save the reference as I was working on something else.

Found another source and it says you can modify the VEXeppressions.txt file

But everytime I try to save changes I get an error message as in the post title.

I tried doing it while no version of Houdini was open, checked file if it was ticked as ‘read’ only, and off chance it had something to do with it - have administrative rights.

It seems the only way I can access and add to that file is from someplace within Houdini itslef.

Anyone know?

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Joined: Sept. 2011
The houdini file system can have as many sources as you want. The first location, the install directory, is only the bare minimum to run houdini. Nearly any file in the Houdini path can be overridden/appended to by files later in the path. By default, your home directory contains a folder in the houdini path. If you want to override a file from the install, note the filename and path from the houdini install root, and mirror it in your home directory. This will allow user specific versions of most files. Some files, such as otls, don't have an order of precedence inherited from the path.

To make your own vexpressions, put a file in your home houdini folder called ‘VEXpressions.txt’.

So you don't ‘edit’ the install files, you override/append with your own files further down the path.
Edited by jsmack - June 10, 2017 22:17:34
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1101 posts
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Hmmm..thanks for the explanation jsmack.

But I think my lack of understanding this part of Houdini is showing through, and not understanding what your saying, as I'm not able to get it working;
- Have the custom vex expression show up in the wrangle drop down menu.

The installed VEXpression.txt file lies in : C:\Program Files\Side Effects Software\Houdini 16.0.600\houdini

I did an ‘echo $HOME’ to find out what my home directory, which is:


So within that directory I've tried placing VEXpression.txt(a copy of the original with the additional expressions) in a number of places to try and get it to work, including creating folders to ‘mirror’ what it looks like in the install direcory.

None of these worked:

C:\Users\Me\Side Effects Software\Houdini16.0.600\houdini\VEXpression.txt
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