Split in Chunks script Merge Back option leaves only the re aligned cameras?

[MitchellT]

I have a chunk that has 529 Cameras, 414742 tie points, and dense cloud of 128,115,016 points than runs out of memory (32 meg) trying to build the mesh. I tried using the Split in Chunks script, without selecting merge back and exported the 9  chunks of mesh into Zbrush and assembled them there.

As it ran it the first time,  I noticed the seductive merge back button, and tried it several times. It builds the meshes, depth maps and then only returns a merged chunk with with just 529 aligned cameras.

Bug, user error?  (I tried rebuilding dense cloud, auto save and of course build mesh with all the same result)

I will send the log file to support.

Mitchell

[Alexey Pasumansky]

Hello Mitchell,

Removing the minor chunks and camera duplicates when the Merge Back option is used, is the feature of the split in blocks script sample. If you also want to keep the smaller duplicated chunks, you can comment the part in the script that is deleting the cameras from them before merging and removing the chunks themselves after the merging is completed.

[MitchellT]

Thanks Alexey.

I don't understand what is the purpose of the merge back button. I am also having trouble understanding your suggestion.

 I use the script wanting to build the full mesh, that can't be built  from the full dense cloud, due the large number of points, and relatively low memory.

Not being a coder, and liking efficiency, can you tell me how to automatically merge the meshes created in the  minor chunks back together to return the complete mesh?

Thanks,

Mitchell

[Alexey Pasumansky]

Hello Mitchell,

Merge back function is usually suggest to be used in the following scenario:
- source chunk is split into grid of smaller chunks (all cameras are duplicated for each chunk copy),
- dense cloud / mesh are generated for each smaller chunk,
- smaller dense clouds / meshes are merged to the new chunk,
- only single set of aligned cameras is copied to the merged chunk (for this purposes the cameras for the smaller chunks have been removed prior to merging),
- smaller chunks are removed after merging the surface to the new chunk.

In the end you'll get the source chunk, and "merged chunk" with the same alignment, but combined surface (dense cloud / mesh). No other chunk are left in the project.

If you haven't enabled Merge Back function in the script dialog and end with multiple chunks with the smaller mesh fragments, then you can just go to Merge Chunks operation in the Workflow menu and select all the chunks.
To avoid the cameras being duplicated in the merged chunk you can:
- remove all the cameras from each smaller chunks before merging,
- remove the dense clouds from the smaller chunks before merging (if you have the same in the source chunk),
- include the source chunk to the Merge Chunks operation.