Before slicing, my object to be printed (a tree) looks like I want it to look.
Post-slicing, my tree has been trimmed and I get floating pieces and empty layers.
Can someone tell me what is going on here to cause this?
I ask because it might help me design better objects to be printed (specifically trees).
You cannot print the downward sloping branches without supports, the branches are too thin to print, and even if they were thickened, they would probably break during support removal. The model is not a good candidate for FDM printing.
Thank you for your response.
I know it is not a good candidate for FDM printing but I need to know why the slicing eliminates parts of my tree which results in floating pieces and empty layers.
I am trying to understand the workings of the slicer so I can create better models.
Can you tell me why the slicer prunes the trees to leave floating pieces and empty layers?
Start from scratch 
What is the smallest line in your model ?
Those branches look VERY slim to me.
You can’t expect a printer with a 0.4mm nozzle to print things much finer than that.
Same for the complexity per layer.
You have a ton of isolated islands to be printed, all just tiny dots…
A total nightmare in FDM, one to be avoided…
Forget about the weeding cherry parts unless you want to use more support material than what the model uses.
May I ask why you try print such organic trees ?
This is just a guess based on your images but I get the feeling that the slicer converts the model into 2D images (like resin slicers). The print settings determine the pixel density and the volume of many parts of your model is to thin to fill those pixels. Remember resizing many images as a kid and they looked the same way 
Generally speaking, it is a bad model for FDM printing. A good tree would probably have 5% of the branches and each one would be MUCH thicker. A good way to compensate is to sculpt texture into branches and leaves.
I can a
Here is a good example of more suitable trees. Rocket Pig Games - Canopy Trees: https://www.myminifactory.com/object/3d-print-canopy-trees-163360
@user_3026326371 Thank you for commenting and for the questions.
I am unsure what model you are speaking about (either digital or physical), so I will give both:
When the model was brought into Bambu Studio, it was scaled up 500%.
The reason for making such organic trees is twofold:
I saw some beautifully printed trees on this video: https://youtu.be/4aFaeu6LvLc, but I have no idea what printer was used.
I guess my main question would be:
What are those isolated islands and how did they appear?
Thank you for your assistance. It is much appreciated.
@Skogstrollet Thank you for responding with great information. I am guessing that what you saw as a kid is probably exactly the result I have.
From what I get from your response (please correct me if I am wrong), in order to have leaves printed (which currently they do not), the leaves would have to have much more width and thickness and be connected to much thicker branches.
Thanks also for the link; I see what you mean by larger and fewer.
The video is pretty vague about which technology they used for which part of their models. I think they used powders fused with a laser to create the trees.
Islands:
I define areas like that which have no connection to the rest of the model on the layer.
Like those tree branches bending down and with their tip BELOW the rest of the branch.
These have to be printed with support from below and if VERY small and thin ARE a PAIN for FDM.
Upscaling by 500% results in your 0.174mm branches still being just under ONE mm thick.
That is literally like trying to print a dot.
Anything OVER 0.4mm wide is not a problem IF it is horizontal, your tree parts are from it.
The video you linked shows architectural design features offered by a printing company but neither specifies how the trees were created nor if they were printed in one piece, not even if the fluff was added manually.
I know for a fact that there is companies selling trees, shrubs and lots more at a scale used for most design and hobby projects.
One example is the world of train models.
I tried printing something similar to a tree with my resin printer and gave up trying.
Certain things just can’t be printed and need to be created the traditional way
Thank you for the great explanation. I will give up for now, but will hope for a cleaner resin-printing setup sometime in the future, even if it is years from now.
I looked at their website and it appears they use top-down resin printing for some of their high-end prints. Too expensive for me. Darn. Thank you for your reply.
The trees and other decorations people use are usually conventional models, the ones in the video are not 3D printed.
