Can someone clarify the 'Overwrite' option in the Import A3d dialouge box?

Question

I've played around with exporting lights out of VW and importing the .a3d file into Eos both with the Overwrite field checked and not checked...I'm not seeing different behavior. Can someone clarify what exactly that option is doing how I could see it in action? 
 thanks Cory

starksk · Answer

Hi Cory Pattak , 
 When the Overwrite option is disabled (x), the import from .a3d (or Lightwright) will merge with the existing patch data where there are no conflicts. For example, if we start with a 1 to 1 patch and then import from your test .vwx from one of your other posts, we would keep the addresses since your .vwx didn't include the addresses and gain the positional data. 
 When the Overwrite option is enabled (check), the import from .a3d (or Lightwright) will replace the data that is existing for the channel, even if the incoming data is empty. Again starting with the 1 to 1 patch and importing from your test .vwx, you would see the addresses for the first 4 fixtures be removed since your .vwx didn't include the addresses and we would gain the positional data. 
 If you are starting from an empty show file, there is no functional difference since there is no data to conflict or replace.

starksk · Answer

Hi Cory Pattak , 
 I agree that this is confusing and there are definitely internal discussions going on about how to make this better. 
 Here are the general rules as they currently stand (3.0.1) for overwrite on import (note that both Vectorworks and Lightwright use the same rules): 
 
 If overwrite is selected, data from the import file will replace data from the target file even if it is blank in the import file. 
 If overwrite is deselected, where data exists in the import file but does not exist in the target file, the import file data is added to the target file. Where data exists in both the import file and the target file, the import file's data is used when address assignment to channels matches in both files. Existing data in the target file is not removed when it is not present in the import file.
 
 If multiple addresses are assigned to a single channel, new parts will be created. 
 If the import's data for channel and address do not match the target's data for channel and address on part 1 of the channel, part 1 will be overwritten with the import data instead of creating an additional part.
 
 Example: Say you have an existing file with channel 1 patched as a dimmer to address 5. You have a Vectorworks file you are importing from that has 2 fixtures for channel 1 addressed on addresses 1 and 2. On merge, because part 1 does not match the channel and address assignment, address 5 is overwritten with the data for address 1 and a second part is created for address 2 on channel 1.

So for single part channels where the address and channel data do not match in the import vs target files, merge and overwrite will be functionally the same.