Preform warns about overlapping models and highlights parts touching each other in red. I recognize others may like the feature, but after trying it for a while I find it of limited utility and really more of a distraction than helpful. I’d like to hear what you think.
I typically conjoin the rafts of my parts in order to:
Pack models more tightly (print more per job)
Reduce manual labor after the print
Reduce resin use
I’ve been running prints for other people lately, and I’ve noticed #2 has particular impact. A single big part is a heck of a lot quicker to detach from the build platform than a bunch of individual little ones (and tends to suffer a lower “casualty rate”). It also cuts down on touchpoints during post-processing when items are moved, one by one, from each step to the next (wash, dry, cure, etc).
The warning and red highlighting would be an absolute killer feature for me if it were modified to only complain when the geometry of my actual parts touch, and ignore overlapping bases / supports.
I realize prints can be more successful when there’s ample space between parts, and the existing warning encourages new users to space things out. But as long as I don’t go overboard, I’ve never really run into problems packing parts. If it’s a concern, you could define a [hopefully user-adjustable] collision margin.
A lot of other users like to overlap their rafts / support structures. Just search the forums for “overlap”. Implementing their much-requested feature to integrate overlapping bases (originally motivated by users who wanted to avoid the unnecessary wear on PDMS from double-drawing the laser path) would go a long way toward solving this for me, assuming Preform’s collision check were applied after said integration.
Using Preform 2.13.1, the red warning works exactly as you describe : parts only become red when the actual part geometries overlap, or when support material comes into contact with a part, but not when the supports or rafts overlap each other. I find it incredibly useful to manually pack a maximum of complex parts in one print.
I think it would be great for preform to have a feature to “adapt the rafts” after you positioned everything so as to avoid double exposing the overlapping features, but other that that I’m personally quite happy with how it works.
Maybe @fogleman, who worked on the new layout feature in preform and apparently is also working on the same feature for the incoming Fuse, may be able to confirm or contradict this
Could you have a look at it for me? As far as I can tell the chairs themselves aren’t touching each other or each other’s supports, but they’re highlighted red.
My build platform was packed with cases like this and I must have erroneously concluded it was due to raft contact. Next time I’ll have to investigate more thoroughly before posting.
I think the warning might also come up if I have a portion of a part protruding too far “overtop” or “looping around” another one (again, investigation required).
Maybe @fogleman can chime in more authoritatively on exactly how collisions are detected, to assuage my confusion (e.g. boundary margins, if there’s projection onto 2D plane of build platform happening, etc).
In the meantime, apologies and kudos to him and Formlabs; it seems they implemented the feature exactly the way I wished for (or at least with pretty close intent).
I also expected this to be an issue but I tested this a short while ago and it’s not the case.
As for your file, if you move that parts just a bit further away from each other the warning stops.
My interpretation is that there is a minimal distance between two geometries that triggers the red outline even if the parts don’t touch each other, this may be because of an approximation in the layout tool… or it could be voluntary to avoid resin clogging and curing in between two parts.
I personally don’t see this as an issue because of how little the gap is before the part becomes red, but then of course it depends on the size of the part itself. EDIT : it is especially a non issue since you can launch the print anyway, you just have to be really sure the models aren’t touching each others unless you want them to.
