{"id":1292,"date":"2012-02-22T00:01:21","date_gmt":"2012-02-21T22:01:21","guid":{"rendered":"http:\/\/www.smart-page.net\/blog\/?p=1292"},"modified":"2012-02-22T01:39:52","modified_gmt":"2012-02-21T23:39:52","slug":"smart-hn-options-cinema-4d-python-commanddata-plugin-template","status":"publish","type":"post","link":"http:\/\/www.smart-page.net\/blog\/2012\/02\/22\/smart-hn-options-cinema-4d-python-commanddata-plugin-template\/","title":{"rendered":"Smart HN-Options – Cinema 4D Python CommandData Plugin Template"},"content":{"rendered":"

So far we already covered IDE-setup<\/a> and debugging<\/a> – new let’s go and actually build something!
\n
\nThis is meant to be a simple template of the most common plugin type in Cinema 4D – the CommandData plugin.<\/p>\n

Smart HN-Options is a very simple tool that allows to globally change the parameters of every HyperNURBS object within the scene.<\/p>\n

Grab the plugin and source! (Eclipse project files included)<\/a><\/p>\n


\n
I had this lying around some time now and thought it would made for an excellent example since its small, very<\/b> basic and couldn\u2019t have been a Script Manager script as it needs to ask the user for multiple parameters on each run.<\/p>\n

The code is commented and self-explanatory – i hope – but let\u2019s go through the abstract structure quickly:
\n<\/p>\n

STEP 1: PYP-File and Package<\/h2>\n

As with each python plugin, we start by creating a sub-folder in \/Plugins<\/em> and a *.pyp file within it – in this case the SmartHNOptions.pyp<\/em>.
\nFirst we add the directory that file resides in to the python search path, so the interpreter will pick up our packages and modules:<\/p>\n

import os\r\nimport sys\r\n\r\n# add this plugin to the python search path\r\nfolder = os.path.dirname(__file__)\r\nif folder not in sys.path:\r\n    sys.path.insert(0, folder)<\/code><\/span><\/pre>\n
<\/p>\n
The SmartHNOptions.pyp<\/em>\u00a0will also have to register our plugin with Cinema 4D, but let’s do that later and finish the general structure first.<\/p>\n
Your plugins should exist of at least one package which should be named after the plugin – try to come up with unique names here so you don’t collide with other plugins.<\/p>\n
I called it smarthnoptions<\/em>\u00a0and placed an empty __init__.py<\/em> file within the folder immediately – without that file the package will be ignored.
\n<\/p>\n
STEP 2: RES-Folder<\/h2>\n
\"\"<\/p>\n
Then we create another subfolder next to the smarthnoptions<\/em> package – the res<\/em> folder.<\/p>\n
The res<\/em> folder includes everything Cinema 4D will need to create and handle the GUI for your plugin – symbols, strings, the layout and images or other assets.<\/p>\n
You just have to follow conventions here – the res<\/em> folder always includes the c4d_symbols.h<\/em>\u00a0– the header file which includes an enumeration of symbols used to identify every GUI-object or string you use – and at least two folders:
\ndialogs<\/em> and strings_us<\/em> (only if your CommandData plugin actually has a dialog – otherwise you may skip the dialog<\/em> folder(s)). strings_us<\/em> also includes another dialog<\/em> directory.<\/p>\n
For each dialog there is a [dialog name].res<\/em> file within the dialog<\/em> folder and a [dialog name].str<\/em> within strings_us\/dialog<\/em>.
\nThe *.res file describes the dialogs layout, the *.str file the strings used by those GUI-elements.<\/p>\n
Last but not least there is a c4d_strings.str<\/em> file directly within the strings_us<\/em> folder – this one is used for all strings you need to load on runtime (error-messages etc).<\/p>\n
As you might have already guessed, the strings_us<\/em> folder has the ‘_us’ extension because this is the default – but you can add a ‘strings_de’ folder for example and localize your plugin to German – or French, Italian, Japanese…
\n
\nThis about covers the res<\/em> folder – have a look at the provided files and I encourage you to read up on the topic in the documentation (misc\/pluginstructure.html).
\n<\/p>\n
STEP 3: Hack away…<\/h2>\n
\"\"<\/p>\n
Let’s finish the boring part and lay out the python part of our plugin:<\/p>\n
We will need a convenient way to reference to GUI-elements by their correct symbol ID which was specified within the c4d_symbols.h<\/em>.<\/p>\n
So I created a ids.py<\/em>\u00a0file and basically copied the constants from the enum into it.
\nThus we can import that file and refer to GUI-elements by their constant name and don’t have to juggle a lot of abstract numbers.<\/p>\n
If you are building a huge plugin, you might want to consider parsing the c4d_symbols.h<\/em>, but that\u2019s a future post…<\/p>\n
Then I created a cmddata.py<\/em> – short for CommandData (avoid using names from the Cinema 4D API!).<\/p>\n
# this class is the basic plugin
\nclass CMDData(c4d.plugins.CommandData):<\/span><\/code>
\n<\/p>\n
It includes a class that derives from c4d.plugins.CommandData and is the plugin in itself – once executed (Execute()<\/em>) it creates the dialog.<\/p>\n
The dialog however is another *.py file – maindialog.py<\/em> which derives from c4d.gui.GeDialog – it will load it’s layout from the maindialog.res<\/em> and start the actual script which I called worker.py<\/em>.<\/p>\n
Now we head back to the SmartHNOptions.pyp<\/em> and import the ids, cmddata and maindialog.<\/p>\n
Note this detail: the maindialog is injected the GeResource object __res__<\/em> into its module scope, this will enable API functions such as LoadDialogResource()<\/em> or GeLoadString()<\/em>\u00a0to access the plugins resources.
\n
\n# make the GeResource object available to modules which need
\n#access to the *.res or *.str files
\nmaindialog.__res__ = __res__<\/code><\/span>
\n
\nAnd finally – once the file is executed, we quickly load the icon and register the plugin with Cinema 4D.<\/p>\n
# register the plugin
\nif __name__ == \"__main__\":<\/span><\/p>\n
\u00a0 \u00a0 # load an icon<\/span>
\n\u00a0 \u00a0 icon = c4d.bitmaps.BaseBitmap()<\/span>
\n\u00a0 \u00a0 icon.InitWith(os.path.join(os.path.dirname(__file__), \"res\", \"icon.tif\"))<\/span><\/p>\n
\u00a0 \u00a0 # get the plugin title from the string resource<\/span>
\n\u00a0 \u00a0 title = c4d.plugins.GeLoadString(ids.STR_TITLE)<\/span><\/p>\n
\u00a0 \u00a0 c4d.plugins.RegisterCommandPlugin(ids.PLUGINID, title, 0, icon, title, cmddata.CMDData())<\/code><\/span>
\n
\nFrom here on, things should be obvious from the source and comments – please let me know if you have any questions or suggestions.
\n
\nHappy plugin coding!<\/p>\n","protected":false},"excerpt":{"rendered":"
So far we already covered IDE-setup and debugging – new let’s go and actually build something! This is meant to be a simple template of the most common plugin type in Cinema 4D – the CommandData plugin. Smart HN-Options is a very simple tool that allows to globally change the parameters of every HyperNURBS object within the scene. Grab the plugin and source! (Eclipse project … Continue reading Smart HN-Options – Cinema 4D Python CommandData Plugin Template<\/span> »<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[52,53,1,88],"tags":[175,184,185],"_links":{"self":[{"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/posts\/1292"}],"collection":[{"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/comments?post=1292"}],"version-history":[{"count":62,"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/posts\/1292\/revisions"}],"predecessor-version":[{"id":1358,"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/posts\/1292\/revisions\/1358"}],"wp:attachment":[{"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/media?parent=1292"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/categories?post=1292"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.smart-page.net\/blog\/wp-json\/wp\/v2\/tags?post=1292"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}