Messages between objects [SOLVED]

On 03/04/2015 at 19:07, xxxxxxxx wrote:

Hello,

thinking about communication between objects in a scene, it would be great if someone can give me a hint.
E.g. I have a python generator object in my scene with a user data link field.
The geometry of the linked object is part of the generator calculation.
With disabled cache optimization I can handle the dirty state of the generator by myself.
Additionally with another global dirty variable for the linked object I can detect if the linked one has changed that the generator can update properly.

Is there a better way to manage such a task, it seems dirty?

Thanks in advance
Martin

On 07/04/2015 at 07:43, xxxxxxxx wrote:

Hi Martin,

You seem to be doing this the right way.
But how do you handle the global dirty variable for the linked object?
Also what method do you call? C4DAtom.GetDirty() or BaseObject.IsDirty() or C4DAtom.GetHDirty()?

On 09/04/2015 at 00:02, xxxxxxxx wrote:

Hi Martin,

What I do is instead of having a link, I put the object as a child under my generator.
This way the generator is triggered if the object is changed or an object is placed under the generator.

-Pim

On 09/04/2015 at 02:46, xxxxxxxx wrote:

Hello,

@Pim:
This doesn´t work for me. I need unique link fields for several objects which are treated in a specific order and way. Therefore I don´t want to force the user to keep an eye on a hierarchy or even don´t want to explain it to the user. Nevertheless, could you post an example please, I can´t see how your suggestion should work with e.g. point modifcations or deformer.

@Yannick
I´ll post a simple example here.
For the linked object I use GetDirty() and raise the global variable of my generator to update accordingly.
I would be glad if there is a better way and also if the example is the right way. Thanks!

Best wishes
Martin

  
import c4d, random  
from c4d import utils  
  
global dcount  
dcount = 0  
   
  
def GetLink(op) :  
  link = op[c4d.ID_USERDATA,1]  
  if not link:return  
  if not link.IsInstanceOf(c4d.Opolygon) :link = link.GetCache()  
  deform = link.GetDeformCache()  
  if deform:  
      link = deform  
  return link  
  
def main() :  
  global dcount  
  op[c4d.OPYTHON_OPTIMIZE] = False  
  vor = GetLink(op)  
  if not vor:return  
       
  #_____________________________________________________  
  #custom dirty test with linked object             
  vdirty = vor.GetDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX)  
  if vor.GetDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX) :          
      if dcount != vdirty:  
          dcount = vdirty  
          op.SetDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX)            
  if not op.IsDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX) :return op.GetCache()  
    
    
  #_____________________________________________________  
  #parent virtual object  
  null = c4d.BaseObject(c4d.Onull)  
  child = vor.GetClone()  
  #child.SetMg(op.GetMg())  
  child.InsertUnder(null)  
    
  return null  
  

On 09/04/2015 at 03:32, xxxxxxxx wrote:

Hi Martin,

I have a text and spline below the generator:
- first I check whether both are give, using node.GetDown()
- then I check whether another object is given, using a previous value
- then I check whether the objects are changed (dirty)
In these case I set the node to dirty

If the node is dirty - do whatever you want to do.

You know me, perhaps not optimal and efficient, but it is working.

    def GetVirtualObjects(self, node, hierarchyhelp) :
    
        doc = documents.GetActiveDocument()
        frame = doc.GetTime().GetFrame(doc.GetFps()) 
  
        #check of text+spline is given
        if (node.GetDown() is None) : return             #Text
        if (node.GetDown().GetNext() is None) : return   #Spline
         
        # Text given changed?
        if node.GetDown() != self.text:
            self.text = node.GetDown()
            #print "text source: ", self.text
            node.SetDirty(c4d.DIRTY_DATA)
  
        # Spline given changed?            
        if (self.text.GetNext() != self.boven) :
            self.boven = self.text.GetNext()
            node.SetDirty(c4d.DIRTY_DATA)
        
        if (self.boven.GetType() != c4d.Ospline) : 
            #print "Not a spline"
            return
        
        # Text changed (dirty)?
        if node.GetDown() and node.GetDown().IsDirty(c4d.DIRTY_DATA | c4d.DIRTY_MATRIX) :
            node.SetDirty(c4d.DIRTY_DATA)
            #print "Set dirty text."
  
        # Spline changed (dirty)?
        if node.GetDown().GetNext() and node.GetDown().GetNext().IsDirty(c4d.DIRTY_DATA | c4d.DIRTY_MATRIX) :
            node.SetDirty(c4d.DIRTY_DATA)
            #print "Set dirty spline boven."
  
.....

-Pim

On 09/04/2015 at 03:59, xxxxxxxx wrote:

Hi Martin,

Originally posted by xxxxxxxx

@Yannick
I´ll post a simple example here.
For the linked object I use GetDirty() and raise the global variable of my generator to update accordingly.
I would be glad if there is a better way and also if the example is the right way. Thanks!

Your Python generator script seems to work fine but I've found 2 minor issues:

To prevent errors in GetLink() you should check if the user data exists and if it's really a link:

def GetLink(op) :
    udOK = False
    for udID, udBC in op.GetUserDataContainer() :
        if udID[1].id==1 and udID[1].dtype==c4d.DTYPE_BASELISTLINK:
            udOK = True
            break
    
    print "User Data OK : " + str(udOK)
    if not udOK: return
    
    link = op[c4d.ID_USERDATA,1]
    if not link:return
    if not link.IsInstanceOf(c4d.Opolygon) :link = link.GetCache()
    deform = link.GetDeformCache()
    if deform:
        link = deform
    return link

Also the document's dirty state is always set because "Optimize Cache" is disabled in the generator main():

  
op[c4d.OPYTHON_OPTIMIZE] = False

This should be disabled upon generator's creation and a warning should be printed if it's enabled again.

On 09/04/2015 at 07:07, xxxxxxxx wrote:

Hi Pim, Hi Yannick

@Pim
The problem with the IsDirty() function and a generator object is, that IsDirty() seems to be hierarchy dependent.
Within your child structure this might be possible, but with a link field where the object can be anywhere in the hierarchy your example wont work. Anyway, thanks for your effort.

@Yannick
Thanks for the hints and lines!

Originally posted by xxxxxxxx

To prevent errors in GetLink() you should check if the user data exists and if it's really a link:

Thinking further about what could happen in the worst case, I figured out that there is even another case I need to cover.

    if not link.IsInstanceOf(c4d.Opolygon) :link = link.GetCache()

This line produces an error if the linked atom is a material. I used try except...

Another problem occured!
If the linked object is a primitiv, the dirty check only triggers once and after that the generator wont update anymore.
Could you please tell me what´s wrong with the code?

  
import c4d, random  
from c4d import utils,gui  
  
global dcount  
dcount = 0  
   
  
def GetLink(op) :  
  udOK = False  
  for udID, udBC in op.GetUserDataContainer() :  
      if udID[1].id==1 and udID[1].dtype==c4d.DTYPE_BASELISTLINK:  
          udOK = True  
          break          
  if not udOK:          
      dialog=gui.MessageDialog("No appropriate UserData available! \n"  
                              "Please insert a linkfield \n"  
                               "and activate the generator again.",c4d.GEMB_OK)  
      op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False    
      return  
  link = op[c4d.ID_USERDATA,1]  
  if not link: return  
  if not link.IsInstanceOf(c4d.Opolygon) :   
      try:  
          link = link.GetCache()  
      except: return  
        
  deform = link.GetDeformCache()  
  if deform:  
      link = deform  
  return link  
  
def main() :  
  global dcount  
  if op[c4d.OPYTHON_OPTIMIZE] == True:  
      dialog=gui.MessageDialog("Please uncheck Optimize Cache! \n"  
                               "and activate the generator again.",c4d.GEMB_OK)  
      op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False   
      return          
  vor = GetLink(op)  
  if not vor:return  
       
  #_____________________________________________________  
  #custom dirty test with linked object             
  vdirty = vor.GetDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX)  
  
  if vdirty:                
      if dcount != vdirty:  
          print "dirty"  
          dcount = vdirty  
          op.SetDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX)            
  if not op.IsDirty(c4d.DIRTY_DATA|c4d.DIRTY_MATRIX) :return op.GetCache()  
    
    
  #_____________________________________________________  
  #parent virtual object  
  null = c4d.BaseObject(c4d.Onull)  
  child = vor.GetClone()  
  #child.SetMg(op.GetMg())  
  child.InsertUnder(null)  
    
  return null  
  

Thanks in advance !
Best wishes
Martin

On 09/04/2015 at 09:24, xxxxxxxx wrote:

Originally posted by xxxxxxxx

if not link.IsInstanceOf(c4d.Opolygon) :link = link.GetCache()
This line produces an error if the linked atom is a material. I used try except...

I think you'd better check the classification of the linked base list and discard all that aren't objects, in Obase classification.

Originally posted by xxxxxxxx

Another problem occured!
If the linked object is a primitiv, the dirty check only triggers once and after that the generator wont update anymore.
Could you please tell me what´s wrong with the code?

You're getting the dirty checksum of the cache, not of the actual object, in the case of a primitive.
I think you'd better have 2 functions: one to get the linked object and another to get the linked geometry.

Also, an object (at least an empty Null object in the case of an error) should be always returned by a generator, otherwise Cinema 4D will try to rebuild the cache again and again.

Here's the working code I came up with:

import c4d
from c4d import utils, gui
  
global dirtyCount
dirtyCount = 0
  
def GetLink(op) :
    udOK = False
    for udID, udBC in op.GetUserDataContainer() :
        if udID[1].id==1 and udID[1].dtype==c4d.DTYPE_BASELISTLINK:
            udOK = True
            break
    if not udOK:
        dialog = gui.MessageDialog("No appropriate UserData available! \n"
                                   "Please insert a linkfield \n"
                                   "and activate the generator again.",c4d.GEMB_OK)
        op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False
        return None
    
    link = op[c4d.ID_USERDATA,1]
  
    if link.GetClassification()!=c4d.Obase:
        dialog = gui.MessageDialog("Please insert a valid object in the user data link!",c4d.GEMB_OK)
        op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False
        return None
    
    return link
    
  
def GetGeom(op) :
    geom = op
    if not op.IsInstanceOf(c4d.Opolygon) :
        geom = op.GetCache()
    deform = geom.GetDeformCache()
    if deform:
        geom = deform
    return geom
  
  
def main() :
    global dirtyCount
    
    if op[c4d.OPYTHON_OPTIMIZE] == True:
        dialog=gui.MessageDialog("Please uncheck Optimize Cache! \n"
                                 "and activate the generator again.",c4d.GEMB_OK)
        op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False 
        return c4d.BaseObject(c4d.Onull)
    
    link = GetLink(op)
    if not link: return c4d.BaseObject(c4d.Onull)
    
    #custom dirty test with linked object
    dirty = link.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)
    if dirty != dirtyCount:
        print "Dirty"
        dirtyCount = dirty
        op.SetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)
    else:
        print "Not Dirty"
    
    if not op.IsDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX) : return op.GetCache()
    
    geom = GetGeom(link)
  
    #parent virtual object
    null = c4d.BaseObject(c4d.Onull)
    child = geom.GetClone()
    #child.SetMg(op.GetMg())
    child.InsertUnder(null)
    
    return null

On 09/04/2015 at 18:04, xxxxxxxx wrote:

Hi Yannick,

thanks a lot for developing this further with me!
That was the solution to differentiate the link itself and the geometry, great!
And good to know that the generator needs a least one object to return.
Two minor issues, but really minimal:
After line 20 in your code there must be another if not clause, if there is no object in the link field.
Otherwise an error occured None doesn´t have GetClassification().
And the GetGeom function needs to be called before the dirty check lines, that the deform cache could be taken into account while checking the dirty state.

Again, that was very helpful thanks.
One can do a lot of nice stuff with this combination, generator and linked object.

Best wishes
Martin

On 10/04/2015 at 00:33, xxxxxxxx wrote:

Hi Martin,

You're welcome. Thanks for pointing the errors in my code.
I'll tag the topic as solved.

On 10/04/2015 at 00:34, xxxxxxxx wrote:

Hi Yannick,

I guess I was overhasty stating that your code is the solution.
If you change an attribute of a primitiv in the link field it again wont work.
Also if you grab the handels and scale the primitiv, the generator won´t reflect this.
What else could be wrong?
Sorry to bother you again.

Best wishes
Martin

On 10/04/2015 at 00:36, xxxxxxxx wrote:

Originally posted by xxxxxxxx

I guess I was overhasty stating that your code is the solution.
If you change an attribute of a primitiv in the link field it again wont work.
Also if you grab the handels and scale the primitiv, the generator won´t reflect this.
What else could be wrong?

Are you checking the dirty on the linked primitive object and not on its cache?

On 10/04/2015 at 01:04, xxxxxxxx wrote:

Hi Yannick,

this is driving me nuts, even if I differentiate the dirtytest within the GetGeom function and pass the value.
I´m always one step behind the update.
If you e.g. change a parameter of the primitiv numerically and press enter, nothing happens.
Thanks in advance for your patience!

Martin

  
import c4d  
from c4d import utils, gui  
  
global dirtyCount  
dirtyCount = 0  
  
def GetLink(op) :  
  udOK = False  
  for udID, udBC in op.GetUserDataContainer() :  
      if udID[1].id==1 and udID[1].dtype==c4d.DTYPE_BASELISTLINK:  
          udOK = True  
          break  
  if not udOK:  
      dialog = gui.MessageDialog("No appropriate UserData available! \n"  
                                 "Please insert a linkfield \n"  
                                 "and activate the generator again.",c4d.GEMB_OK)  
      op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False  
      return None  
    
  link = op[c4d.ID_USERDATA,1]  
  if not link:return None  
  
  if link.GetClassification()!=c4d.Obase:  
      dialog = gui.MessageDialog("Please insert a valid object in the user data link!",c4d.GEMB_OK)  
      op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False  
      return None  
    
  return link  
    
  
def GetGeom(op) :  
  geom = op  
  dirty = op.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
  if not op.IsInstanceOf(c4d.Opolygon) :  
      dirty = op.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
      geom = op.GetCache()  
  deform = geom.GetDeformCache()  
  if deform:         
      dirty = deform.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
      geom = deform  
  return geom,dirty  
  
  
def main() :  
  global dirtyCount  
    
  if op[c4d.OPYTHON_OPTIMIZE] == True:  
      dialog=gui.MessageDialog("Please uncheck Optimize Cache! \n"  
                               "and activate the generator again.",c4d.GEMB_OK)  
      op[c4d.ID_BASEOBJECT_GENERATOR_FLAG] = False   
      return c4d.BaseObject(c4d.Onull)  
    
  link = GetLink(op)  
  if not link: return c4d.BaseObject(c4d.Onull)  
    
  geom,dirty = GetGeom(link)  
    
    
    
  #custom dirty test with linked object  
  #dirty = link.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
  if dirty != dirtyCount:          
      dirtyCount = dirty  
      op.SetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
   
    
  if not op.IsDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX) : return op.GetCache()  
  
  #parent virtual object  
  null = c4d.BaseObject(c4d.Onull)  
  child = geom.GetClone()  
  child.InsertUnder(null)  
    
  return null  

On 10/04/2015 at 01:14, xxxxxxxx wrote:

an additional note.
This behaviour is again hierarchy dependend.
If the primitiv is above the generator in the hierarchy everything works fine.
If the primitiv is below it won´t

On 10/04/2015 at 02:57, xxxxxxxx wrote:

It works fine for me with polygon objects, primitives, deformers etc.

2 notes on GetGeom() :
op.GetDirty() is called twice in the case of a primitive.
It would be better to add the dirty count from op.GetDirty() and deform.GetDirty().

  
def GetGeom(op) :  
  geom = op  
  dirty = op.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
  if not op.IsInstanceOf(c4d.Opolygon) :  
      ~~dirty = op.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)~~  
      geom = op.GetCache()
    deform = geom.GetDeformCache()  
    if deform:         
        dirty = **dirty +** deform.GetDirty(c4d.DIRTYFLAGS_DATA|c4d.DIRTYFLAGS_MATRIX)  
        geom = deform  
    return geom,dirty  

On 10/04/2015 at 04:13, xxxxxxxx wrote:

Hi Yannick,

thanks for the next optimization hint!
But still, the problem with the primitiv exists.
I decided to make a small video and an example file to show you what I was talking about.
I´ll send you a PM.

Thanks for your staying power!
Best wishes
Martin

On 10/04/2015 at 06:51, xxxxxxxx wrote:

Hi Martin,

Thanks for the example scene and video. I've been able to see the issue and reproduce it.
It's strange this only happens when editing the primitive attribute by hand and pressing enter.

I think the problem is with GetCache() in GetGeom(). The cache of the linked primitive object hasn't been updated yet when retrieving it.
The only way to obtain the updated polygonal representation of a primitive object is to call the current state to object command. This command rebuild the cache for the passed object if needed, and then clone the polygonal cache object for you.

On 10/04/2015 at 08:05, xxxxxxxx wrote:

Hi Yannick,

testing further I figured out that this not an update problem.

It´s a problem with what we a getting back from the generators link field.

Getting the cache with link.GetCache() from a parametric object within a linkfield
produces a polygon object within a python tag and a null object with every face as a child inside a generator object.

That seems like a buggy behaviour to me.

Could you please give it a try and confirm or counter my assumption?

Best wishes
Martin

On 10/04/2015 at 09:51, xxxxxxxx wrote:

Originally posted by xxxxxxxx

testing further I figured out that this not an update problem.

It´s a problem with what we a getting back from the generators link field.

Getting the cache with link.GetCache() from a parametric object within a linkfield
produces a polygon object within a python tag and a null object with every face as a child inside a generator object.

That seems like a buggy behaviour to me.

Could you please give it a try and confirm or counter my assumption?

I can't reproduce this strange behavior.
Have you tried the current state to object modelling command solution I explained in my previous post? It seems to work fine in all situations.

Also, please start a new topic if you have different questions than the initial one. This make it easier to follow the topic and search the forum.

On 10/04/2015 at 13:44, xxxxxxxx wrote:

The strange behaviour was gone after I started a new Cinema 4d session and built up a new scene.
Maybe a corruption in between development...

Yannick, I tried your current state to object suggestion, but then I won´t get a valid deform cache from the object nor the deformed polygon object.
With [c4d.MDATA_CURRENTSTATETOOBJECT_NOGENERATE] set to False I should get a deformed object from current state to object.

Could you please post your solution?
I´m a little lost at the moment...
This thread is really not solved for me , sorry

Best wishes
Martin