I’ve tried to place two parts the way that they share part of the base so the resin comsumption can be lower but preform does not recognize it (see pictures below):
In this case the resin safe is minimum but in other cases can be significant,
is there any option in preform that recognise that issue?
Those overlaps will be drawin twice but in my experience it is not a problem. You will get a little resin savings.
You’re not saving a meaningful amount of resin, and where areas overlap the laser will pass over the area twice. This can result in overcuring that makes it hard to get the print off the build platform, and could cause the print to fail because it gets cured too well to the bottom of the resin tank. Not very high odds of a problem, before everyone else jumps in and says they do this all the time. But for the “savings” in resin (at most a few mL) it’s not worth it IMO. You break one print trying to pry it off the platform, you’ve wasted a lot more resin than you might have saved…
But I do this all the time with no issues!
Or I used to. The only reason I found for overlapping bases was to attach smaller rafts to each other or to larger ones with hoods to reduce the annoyance related to removing small objects from the platform. Sticking 10 small parts together by the rafts was a huge time savings in removal.
Now that FL has patched in the re-vamped bases I see absolutely no reason to do it. I agree with Randy 100%
Seems like something that would benefit from not drawing twice (software update?). If the layout is close enough first, before the supports are generated, are the entities still treated as comprised of individual bases?
An arguably better solution to this desire is being discussed over here right now.