Solved CommandData Plugin DrawHUD

gheyret

Hi Everyone！
I want to Draw HUD in the viewport using CommandData Plugin. And i put my 'draw' function in to CommandData.GetState(self, doc)
but nothing happend in the viewport.
And the code like this:

import c4d


_Plugin_id = 20230616
_Plugin_name = "Command_Test"


class Command(c4d.plugins.CommandData):

    def __init__(self):
        self.a = False

    def Execute(self, doc):
        if self.a:
            self.a = False
        else:
            self.a = True
        print(self.a)

        return True

    def GetState(self, doc):
        if self.a:
            print(123)
            bd = doc.GetActiveBaseDraw()
            bd.SetMatrix_Screen()
            bd.DrawHUDText(50,50, "Test HUD")
            
            return c4d.CMD_VALUE | c4d.CMD_ENABLED
        else:
            return c4d.CMD_ENABLED

if __name__ == '__main__':
    c4d.plugins.RegisterCommandPlugin(id=_Plugin_id, str=_Plugin_name, 
                                info=0, icon=None, help='', dat=Command())

And there have another problem: you can see the "print(123)" in the GetState
method for testing, when i click my plugin, cinema4d can print correctly and continuosly in the console, but if i move my mouse to the viewport or click somewhere (like refreshing maybe), the cinema4d has been stucking.
I don't know if I'm wrong or misunderstood something

ferdinand

Hey @gheyret,

Thank you for reaching out to us.

I want to Draw HUD in the viewport using CommandData Plugin.

In short: you cannot draw from a CommandData plugin. A BaseDraw is a container for drawing instructions among other things, not an entity which is actually drawing. When Cinema 4D does not request drawing instructions, you can enqueue as many as you want, they will be ignored. The C++ documentation is even a bit stricter in its wording:

The plugin hooks which provide Draw methods in Python are:

c4d.plugins.FalloffData
c4d.plugins.ToolData
c4d.plugins.TagData
c4d.plugins.ObjectData

In C++ you can also draw with other things such as a ScenehookData which allows for drawing without a tangible entity such as a tool, object, or tag. The best way to emulate this in Python is to use a hidden object.

But you are then still bound to the drawing routine cycle of Cinema 4D. So, when you think that you should print "Hello World!" to the screen, it could still be seconds until Cinema 4D requests drawing instructions from your object.

Because as stated above, with BaseDraw you do not carry out the drawing, you only fill the drawing instructions buffer.

Cheers,
Ferdinand

PS: When you just want to display status information, you should use the status bar related methods.

ferdinand