One thing to be aware of that I've discovered - L3D seems to have a limit on how many block faces it can render. Now, I don't know exactly what does or doesn't count towards this - I've seen a level where this kicks in at around 500 blocks, but there are some official levels with more than that.

One thing I have noticed is - any face touching a block #3, doesn't get rendered - and thus, using block 3 on areas the user will never be able to see, can help avoid this limit. The highest block count is 1227, on Lemlab, a level that very extensively uses block #3. However, the highest block count on a level that doesn't use block 3 at all, which is "A Head Above The Rest", is 825 - well above the 500 that I've seen this effect kick in at.

Anyway, it's probably best to avoid particularly huge levels due to this, at least until we understand exactly how this glitch works.

Uploaded V0.27. Changes:
- Special properties of blocks are now displayed at the bottom of the block selection form (mouseover a block to see details about it).
- Metablocks can now be edited. Right click on a metablock to edit it. Shading can't be edited yet - this was an oversight I only realised after uploading, but won't be difficult at all to implement.
- Bug fix: The 3D-effect shading of block faces stopped working at some point; it's been reimplemented now.
- Bug fix: Negative values for sea movement weren't being accepted; they do now.
- Bug fix: The blue Lemgo sea (and theoretically, any custom seas that share its attributes) did not render correctly; it does now.

Pretty much, the only things remaining now that aren't supported are a few obscure flags (and some unknowns), and land areas, as far as I can think of right now. In particular - you can now create a level truly from scratch, you don't have to import a block setup from another level (though it's still probably easier to do that).

Uploaded V0.26. The only change from V0.25, is that instead of the weird-looking filter effects, it uses an outline to indicate the currently selected layer and block.

I've looked at the remaining unknown bytes (or bit flags, in some cases). Some of them really have no pattern, and we might have to observe closer. However, there's a lot that seem to be the same on all but a few levels.

I'm going to list a few groups of levels, that share currently-unknown values in the data with each other, but different from all levels outside the group. To be very clear - each group is independent. And I realise this is a long shot, but also figured it doesn't hurt to ask.

And just to be clear - it's entirely possible some (or even all) of these are just huge nothingburgers, possibly remnants from the official editor or of features that were removed in the final game, or something like that. So please don't spend too much effort on thinking of it - this is more a "if anything comes to mind, let me know".

Group 1: "Bounce Bounce", "Play Time"
Group 2: "A Shortcut Through The Forest", "Play Time", and all practice levels
Group 3: "This Is The Army", "Stilt Walkers" and "Let The Race Begin"
Group 4: "Alilemms", "Rescue Team" and "The Hanger"
Group 5: All enclosed levels, plus "The Prisoner" and "Claustrophobic" (these last two still have the cameras in enclosed areas, so perhaps it's some setting that relates to that..)
Group 6: "The Bean Machine", "A Shortcut Through The Forest", "Hole in Ten", "Fore!", "Lemlab", "Spaghetti Junction", "Ricochet", "Motherboard", "Birthday Cake", "Brechin's Staircase", "The Hanger", "The Catacombs", "Hole In One, Two, Three", and all practice levels
Group 7: "The Bean Machine", "Alpine Assault Course", "Alilemms", "Jelly Climber", "Oh No! More Pyramids!", "Garden Maze", "King Coder's Tomb", "Rescue Team", "The Arena", "Snake", "The Five Arches", "Brechin's Staircase", "Ski Jump", "Family Tree", "Raiders of the Lost Lemming", "Jelly Belly Islands", "Castle Peralus"
Group 8: "Attack Of The 50ft Lemmings", "Jelly Climber", "A Head Above The Rest", "Play Time", "The Arena", "T Minus 5 And Counting"
Group 9: "A Shortcut Through The Forest", "Stilt Walkers", and all practice levels
Group 10: "Bounce Bounce", "It's A Classic", "Lemlab", "Rescue Team" and "Tuther Circus Level" (with "Picky Platform" having a unique third value, instead of the same one as all other remaining levels)
Group 11: "The M-A-Z-E", "Rescue Team", "Team Work", "Death Slide" and "Slippery"
Group 12: "Alpine Assault Course", "Slippery Maze", "The M-A-Z-E", "Ski Jump" and "The Hanger"

Additionally, can anyone think of any attributes unique to any of the following levels?
- "Take A Dive"
- "Bounce Bounce"
- "Jelly Climber"
- "Lemlab" (other than the laser trap)

Uploaded V0.03. This update removes the need to initialize by loading a known replay.

Next on the todo list is find a way to have automatic saving of replays upon completing a level. At least in theory this should be possible, though I still need to figure out exactly how to best go about detecting this.

Uploaded V0.23. Changes:
- Huge improvements to rendering speed. It's still not great, but now it's just "not great" instead of "awful". I suspect that resolution-wise most people can go to whatever's higher - Medium, or one step up from what they were already using.
- When you import block data from another level, the input field for the current level's texture set is updated to account for this. (The actual level data was always updated, but the text field wasn't, before.)
- If you select a block from the palette, while your current selection is an empty block (ie: none of the slices are present), your current selection is automatically changed back to a full block.

Also as a general rule I wouldnt really look to how Lemmings 2 does things as a guideline for how things should work in a Neolemmix implementation.

Our philosophy with that where applicable has always been "do give consideration to what L2 does, but don't by any means treat it as a golden rule". In the case of Fencer, we gave consideration to how L2 fencer works - and clearly decided "that's not different enough from a basher, it needs a much steeper tunnel" (as opposed to just ignoring the L2 Fencer altogether), while still keeping the overall general idea of a fencer.

In the case of jumper-blocker interaction, I again would feel that L2's rule does not fit with how NL handles other skills and how a user would expect NL to handle Jumper + Blocker.

I've now made the first public release of L3DEdit, so I've created a new topic and thus locked this one.

New topic: https://www.lemmingsforums.net/index.php?topic=4274.0