SOLVED How can I change the order of Reflection layers

Hi,

is there a way to change the order of reflection layers in a material?
Or to create a new reflection layer at the end of the list, instead of always having it as first element?

Thanks & greetings,
Frank

Hi,

I think the short answer is: No. The longer answer is: Yes, but it is incredibly cumbersome (and dicey). The following script will reverse the order of the reflectance layers for the selected material.

import c4d

# Main function
def main():
    """
    """
    # Just get the first active material and check if it is a reflection layer
    # supporting material.
    material_selection = doc.GetActiveMaterials()
    if (material_selection == [] or 
        not material_selection[0].CheckType(c4d.Mmaterial)):
        return
    mat = material_selection[0]

    # Get all reflection layers and their data offset ids for that material
    reflection_layers = [mat.GetReflectionLayerIndex(lid)
                         for lid in range(mat.GetReflectionLayerCount())]
    data_ids = [layer.GetDataID() for layer in reflection_layers]
    
    # Get a copy of the materials data container
    mat_data = mat.GetData()
    
    # I will just reverse the order of the reflection layers (or more precisely
    # the order of the data) to show the principle. Some sort of insertation
    # logic should be trivial to implement for you.
    for old_id, new_id in zip(data_ids, reversed(data_ids)):
        # The reflection layer data is stored in the container of the material
        # with a stride of 512, so for example reflection layer X goes from 
        # SOME_ID to SOME_ID + 511. There are symbols for the stride IDs, check
        # https://tinyurl.com/yxvgmtmt for details.

        # A more safe approach would be to compile a list of that symbols,
        # rather than using that stride approach I use here.
        for i in range(512):
            # We just copy all data from our data container copy to the new
            # location, but there are data types we cannot handle in Python 
            # within that stride, so we need this rather ugly construction.
            # I have no clue what that data is, things might break horribly.

            # !!! THIS MEANS WE EFFECTIVELY WON'T COPY ALL DATA AND MIGHT 
            # GENERATE A CORRUPTED MATERIAL !!!
            try:
                mat[new_id + i] = mat_data[old_id + i]
            except:
                pass
    c4d.EventAdd()

# Execute main()
if __name__=='__main__':
    main()

Cheers
zipit

Thanks, that idea crossed my mind, too. And thank you for even providing code! I was hoping there was a clean way to do that.

SDK team, any further insight about this? Is this possible in a clean way, or maybe in C++ ?

Cheers,
Frank

Hello,

from our point of view there's nothing to move things around. We have only this manual

I have to check to see if there's something hidden but got doubt about it.
I'll be back with information if i find something 🙂

Cheers,
Manuel

hello,

can we change this to solved ?

Cheers,
Manuel