As a follow up to this thread
https://plugincafe.maxon.net/topic/12042/clone-texture-tag-to-children-while-preserving-coordiates/11
I'm posting here some general export issues :
I only worked with the DAE and FBX exporters, can't say anything about the others

The behaviour is not that clear to describe,
but yesterday i finally understood a main part of what is happening:

By default Texture tags are set to UV Mapping and in Cinema4D
the behaviour is so, that this is not a problem, unless you use a texture.
In reality that leads to many tags used with UV Mapping, because
for things like glass, uniformly colored objects etc this is not a problem.

If you export to DAE and FBX the Texture Tags need to get added
to all actual geometry objects, inheritance from parent nulls probably does not work here.
Now if these objects do not have UV tags the inherited materials are ditched/lost
with the result that loads of objects are not materialized anymore.

It also seems that DAE simply doesnt inherit Texture Tags with UV Mapping
down to the children. (Even if they have UV Maps) But It does with Cubic Mapping.

All in all this is a pretty big mess and I am surprised that this was not addressed, yet.

I had a 1+ GB file with thousands of objects and a manual fix was out of question.
The only solution to export it was to:

1. copy all parent texture tags down to the actual geometry (with correct projection/scale/rotation) see here :
   https://plugincafe.maxon.net/topic/12042/clone-texture-tag-to-children-while-preserving-coordiates/11
2. for all objects not having an UV Map, set the projection to Spherical

My solution worked ± for my export, but it is by far not covering all cases.
ie. Cube Object has no UV Tag, but will have after being converted to polygons by the exporter. etc etc

All in all I think... these Exporters really miss some love ;)

best, index

ps. Test Files attached
Export1.c4d Export2.c4d

ah... ok, now i understand the picture !
thanks, manuel

I marked the thread as solved

hi manuel,

thanks... and just to understand...
the screenshot is not from the example above?
(in inherittex5.c4d the child is not skewed)

but i guess its the same problem, right?

I've tried to warp my head around this. The problem is that the tag doesn't store his information of position, scale and rotation with a matrix but with three vectors instead. So you can't add a negative skew to counter the first one. (i hope i'm clear)

yes i understand... but as you can do tag.GetMl() / SetMl() ... is this still not a real matrix? or differently used than the normal object matrices?

i thought, that it might be impossible to fix this in an easy way
but luckily this is a rare special case

best, index

ps. the background of all this was to do an export to fbx/dae
and i found some other issues there...
where would be the proper channel to report that?

thanks a lot!
for others and myself here a reference to the python SDK

https://developers.maxon.net/docs/Cinema4DPythonSDK/html/modules/c4d/C4DAtom/GeListNode/BaseList2D/index.html#BaseList2D.GetInfo

example file :
InheritTex5.c4d

and code :
(not working correctly, due to objects with scale)

import c4d
from c4d import gui

def main():
    parent = doc.SearchObject('parent')
    op = doc.SearchObject('child')
    ptag = parent.GetTag(c4d.Ttexture)
    tag = ptag.GetClone()
    op.InsertTag(tag)

    # handle coordinates / rotation
    tMg = parent.GetMg() * ptag.GetMl() 
    mm = ~op.GetMg() * tMg
    tag.SetMl(mm)

    c4d.EventAdd()

if __name__=='__main__':
    main()

Hi,

is there a simple and safe way to distinct
between non-gemetry objects (like for example nulls/deformers/etc)
and objects having geometry (polygon/loft/sweep/etc) ?

possibly including special cases like generator plugins etc

best, index

here is the example, its just

parent
   null (with a scale)
      child

(all with different positions/rotations)

i had some experience with those translations,
but didnt use them for quite some time...
they're tricky .)

so, thank you a lot for helping here!

@m_magalhaes :

i traverse the complete tree and apply it only for the last child in every branch
(if it doesnt have a tag on its own)

and thanks a lot, the code works!
only if there is a null in the tree with a scale != (1,1,1) things go off.

this is normally not the case, but just out of interest...
would it be possible to handle that so easy, too?
or would you need to traverse-translate down the tree?
parent --> null (with scale) --> child

best, index

@m_magalhaes

Thanks Manuel,

This works for direct children,
but it fails if you add one or more nulls under the parent
with different location/rotation/scale and the child inside the last null..

example:

parent (null) TextureTag
  null
    null      
      null
        child

i try if i can extend your code .)

Here a barebone example not working correctly, yet
just use it with the attached file in the script manager

if the code is right, the cube should get a texture tag
but the texture still look exactly the same as before

from c4d import gui

def main():
    parent = doc.SearchObject('parent')
    op = doc.SearchObject('child')
    ptag = parent.GetTag(c4d.Ttexture)
    tag = ptag.GetClone()
    op.InsertTag(tag)
    
    # handle coordinates / rotation
    # (not working correctly)
    pMg = parent.GetMg()
    oMg = op.GetMg()
    tMl = tag.GetMl()
    t = pMg * oMg
    tag.SetMl(t * tMl)
    
    c4d.EventAdd()

if __name__=='__main__':
    main()

InheritTexExample.c4d