Organic Supports are not fully supporting with Alpha 6, with Alpha 5 they did.

[gregshawdj]

Description of the bug

I have just tried PrusaSlicer Alpha 6 with a Toad egg model and it looks like something has changed for the worse when it comes to organic supports.

Here I have the exact same .3mf file with the same support points sliced with Alpha 5 and Alpha 6. As you can see Alpha 5 does a much better job of having supports ready for the overhang, whereas Alpha 6 have gaps which causes some of the overhangs to be printed in mid air.

Doing a side by side comparison of the support settings (Alpha 6 on the left and Alpha 5 on the right) there is a new setting called branch distance in the organic supports section. I will try some different values to see if I can get what Alpha 5 gives because currently Alpha 5 has the better supports.

Reading the docs that came with the update it mentions 'Organic supports: reduced default support_tree_top_rate to 15%' However this is not a visible setting to change or searchable within the software.

I've added screen shots showing the difference and screen shots using Alpha 6 where you can see an island being printed with no supports underneath. With Alpha 5 there were supports underneath.

Project file & How to reproduce

Hex3D_Toad_Egg_Mono.3mf.zip

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

2.6.0 alpha 6

Operating system

MacOS 12.6.3

Printer model

Creality Ender 5 Pro

[Braintoe]

Description of the bug

I second this (2.6.0 alpha 6 on Linux). For a part that has a radius on the inside going from vertical to almost horizontal, there is no change in the area that is supported with organic supports for a support material threshold value of 80° and 40°, whereas a normal support varies significantly and starts to support overall earlier. It seems Organic Supports largely ignore this setting in this case.

support material threshold value 80° - organic support: support begins to contact part on layer 83:

support material threshold value 80° - standard support: support begins to contact part 8,25 mm earlier - on layer 28:

support material threshold value 40° - organic support: support begins to contact part on layer 83 as well:

support material threshold value 40° - standard support: support begins to contact part 1,2 mm earlier, on layer 75:

Support material contact distance is set to 0 (to be printed with a dedicated support material), support material XY spacing is set to 0,3mm.

Project file & How to reproduce

schale_deckel_3mf.zip

Simply update the two settings "support_material_threshold" and "support_material_style" to the values mentioned above for each case and (re-)slice to get the above results.

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

2.6.0 alpha 6

Operating system

Linux Mint 21.1 Cinnamon

Printer model

Snapmaker J1 (but should be independent of any printer-specific settings)

(edit: updated comment to fit template, replaced STL with project 3MF, added height difference of supports in mm)