Workaround for texturing and UV work using the Samd export:
NOTE: this is a workaround, this is not advised by LL nor by MD. It is just a way to overcome some bugs that currently are in the the Samd created by MD. LL and MD are working to get this fixed. In the end the goal is to get the same UV layout that an OBJ or FBX export would.
At this moment the Samd export leaves you with a very different UV map then the OBJ or FBX export would. Making it complicated to texture the clothing outside of MD. Also the bleed/padding is very poor at this moment, resulting in white borders on pattern edges that show in Sansar. This is certainly not the only work around, many have found their own way to solve the current problems with Samd export. Also some problems occur with roughness, normal and metal maps. Some also caused by poor edge bleeding. You can replace those maps with your own too.
Optional: give all pattern pieces a different color in MD, before export, to identify them later. Using dark colors make it easier later on to see the bleed of the texture.
Export a Samd.
Export an FBX/OBJ.
Unzip the Samd with software of your choice. If you don't have an un-zipper, 7Zip is free to download.
Import FBX/OBJ into Blender or other 3D modeling software.
From here on I describe the Blender workflow, this should easily be done in other 3D apps.
Go into UV Edit mode, check the UV layout of the imported object.
Load the diffuse texture by clicking the Image button in the UV window and opening the diffuse map you got by unzipping the Samd earlier. You can now see the layout that was used by the Samd is very different.
Match your uv to it (use the colors if you used this method to see what goes where).
Re-size and move around till the UV islands fit as well as possible.
(TIP) Re-size the whole pattern at once, checking with one of the pattern pieces if it is lining up so you will not have to resize them one at a time.
Zoom in very close to make sure the uv edges line up with the texture as the bleed is minimal.
Now delete the material(s) of the object and make a new one and use the diffuse texture you used to line up the UV.
Check for seams/white lines... some will occur, that's ok, if they are thin.
Not happy? Adjust the UV again.
Export this FBX/OBJ into your paint program of choice.
Upload the original, unpacked Samd file to Sansar and add the textures you created on upload to Sansar or repack the Samd.
Select all the files (not the folder) then (using 7zip or similar) use the "add archive" option and name archive with .samd file extension.
If you would like to texture in PS or Gimp (free), just use the diffuse you get from unzipping the Samd and paint on it.
In PS/Gimp you would also need to adjust your bleed. Give the the diffuse a matching background or expand the texture edges a few extra pixels.