From your short description, you shouldn't have to fork the engine. Flare mods are created with INI-style text files that set assorted properties for the engine. Clint's "HD" mod works on the latest copy of the engine, so it may be worth looking at: https://github.com/clintbellanger/wandercall-ch1

If you open the Map Properties in Tiled, there should be a custom property called "tileset" with a value such as "tilesetdefs/tileset_cave.txt". This tells the engine which tileset definition to use. The tileset definition sets the tileset images to be loaded and the indicies, bounds, and offsets of the tiles. If the property isn't there, you need to add it yourself.

The format of tileset definitions themselves is documented here: https://github.com/flareteam/flare-engine/wiki/Tile-Set-Definitions

Can you post the contents of the map (in Flare's txt format) and your tilesetdef? It's likely that you need to include the old tileset inside the new one. Try adding this to the top of your new tilesetdef:

[tileset]
INCLUDE tilesetdefs/tileset_garden_ruins.txt

Remember to add [tileset] above your own tileset (see here: https://github.com/flareteam/flare-engine/wiki/Tile-Set-Definitions#multiple-images-in-a-single-tileset-definition)

So from what I see, your "tilesetdefs/sand_128x64.txt" file should look like this:

[tileset]
img=images/tilesets/grass_medium_128x64.png
tile=...

[tileset]
img=images/tilesets/sand_128x64.png
tile=...

In fact, you may want to try using this: https://github.com/flareteam/tilesetdef-generator

Adding another tileset might have altered the IDs of the tiles. Make sure the tile ids in your tilesetdef match what is shown in Tiled. You can check the tile id of the current layer's tile in Tiled by looking at the status bar (see attached image)

I don't think there's a way to fix it in Tiled, but you can edit the TMX file in a text editor to rearrange tileset order. Pay attention to the "firstgid" and "tilecount" attributes of the tileset objects. The firstgid attribute is the only one that would need to change, but the tilecount attribute can help you figure out what firstgid needs to change to.

Here are my suggestions for a new flare mod

Please please have more variety of graphics than the The Empyrean Campaign.  The Empyrean Campaign was nice and long, something really good to see in a free software rpg, but oh boy did some of thosse graphics get repeatative.

Have leveling up actually make stuff better, some of the level ups on skills didn't really seem to improve them.

Equipment was a bit boring, basically just levels and it was too easy to see what gear was better than what other gear, so like more variety, say, multipule atributes on a piece of gear.

Writing - Despite what some people say, I really don't think The Empyrean Campaign was badly writen, while I won't pretend it was the best pieces of ingame lore ever, it was not bad, and quite enjoyable in places.

If you would like some help with quest/storyline writing, I would love to help.

Hey, that looks pretty nice, would be cool to have everything redone like that.

Hey, have you seen the HD ogre and Wyvern models Clint and I made. He and I have been wanting to do a higher resolution version for a while, so it might be worth getting what you can from Clint (advice, assets, etc.)

Looking good. Are you planning on making a swamp tileset? I know you made some swamp plants, but I was thinking about making a whole tileset in that environment, with weeping willow trees, mangroves, etc. Perhaps we can join efforts.

As an observation the graphics in the Flare packages, most of them look great but they are awefully repetitive.  If I had any artistic capabilities I would absolutely spend some time to create some to add to the project.  I think Flare simply needs more variety all the way around.  There are not enough models to go around on enemies, terrain and buildings.  I wish I had enough money to hire a full time graphic artist and release these things in a creative commons license.

A few things I would love to see would be variety in outdoor modular building pieces.  Things like castle walls, stone towers, rickety wood fencing.  Hay bails?  Gardened tiles, like farmland?  I do not think I have seen road/pathway tiles unless I am missing them.  Having something like matching grass texture on two sides but a pebble or sand type path in the middle would be excellent.  I am grateful for what there is to already work because it absolutely helps prototyping my projects.

@reefcrazed: I would encourage you to just dive into Blender and go for it, you'd be surprised at the results you can get with little "artistic capabilities".  And you can always post your stuff on this website and ask for constructive critiques and general feedback.

I may try my hand at it, but I am still a newbie about all of the other portions that are more in tune with my skills, so I have to figure those out first.

@rubberduck It's mostly a matter of preference, but there are some technical reasons as to why you might want to keep them split:

• The sdl_hardware render backend loads images as GPU textures. Depending on the GPU, there can be limits for how large the dimensions of these textures can be.
• While Flare is single-threaded, I've considered introducing threads for asset loading. This could mean an improvement in load times when using multiple smaller tile sheets over a monolitic tile sheet.

@rubberduck: great stuff, as usual.

@dorkster: would that imply multithreading? If so, does that mean that c++11 will be allowed? Specifically, std::thread

@m7600 SDL provides a means of doing multithreading without having to break our "no C++11" rule. I would look at using that before something like std::thread.

Ah, cool. Thanks for the link, I'll look into it. I'm following LazyFoo's lessons on SDL but I haven't gotten to multithreading yet.

Maybe this is too much to ask, but I was hoping for some other types of terrian besides grassland, maybe some desert, swamp or even a field of flowers.

Rubberduck that is simply gorgeous!! i love what you are doing, doesnt feel like its even the same game; any chance of you uploading a video of the tileset on use?

That would also be appreciated, this game lacks practical tutorials really bad; i had a hard time trying to understand spreedsheet making and still have many doubts. Its not accesible to newbies at all.

@rubberduck: looking great.

@Danimal: I think I know what you mean. I think that the problem, in general, is that we tend to assume that other people would have no difficulty in understanding something that we already know. But there's a lot that one can contribute. For example, you might not fully understand how to make a spreadsheet yet, but you do understand how to modify existing 3d models (like the upgraded minotaur you made) and how to make models from scratch (like that snapa kappa creature you posted a while back). So you could contribute with your own tutorials on how to make and modify 3d models. There's Clint's tutorial on how to make isometric tiles in Blender, and dorkster's tutorial on how to make a Flare map, but there's no tutorials on how to make 3d models. 

Well, i think making 3D models is the least needed tutorial, since blender tutorials are something you can find easily around. About modifying them, i guess that could make for a nice tutorial, its actually very easy, since the models are made in a very lazy way (but overly clever and fast).

Havent you guys considered about creating a real guide of "How to´s" for the game? the one in the wiki is hard to understand. Starting from the easiest and going to the most complex; maybe it just needs to present the current tutorials into a simplier way, or going from creating a character to making a simple campaign.

I feel Flare just needs a flashing campaign to be more popular; and overall be more accesible so more people try to do their own.

I still use blender 2.79. I tried the 2.8 version but it was just too different. They changed a lot of keyboard shortcuts for example. I've heard some great reviews about 2.8, though.

Congrats man, its a pretty nice work, will you release a video of it now?

showing the tileset in action / gameplay of the new mod including these tiles?

Yes, that one would be nice; and i guess the first one as well in the future, since your mod might become the new standart of Flare so people can build upon.

Im really curious to se it all in action.