Just a heads up that I've found it to be possible to recreate a tgm file into the tgm spreadsheet. This is great if you want you want to make meaningful and realistic changes using the good work of s397 as a base. This should be amazing for those who want to make road tyres from say, the old nsx tyres or the corvette @vava74 @dylbie I have already succesfully rebuilt the '93 F1 tyres into the spreadsheet with high accuracy, and am now making changes to the shape and construction to replicate the tyres used for the 81-92 f1 seasons, which were different in size and shape. Essentially you can use the data from a compiled tgm to get the nodes for the shape, tread depth, then you can also recontruct the ply layers. I found it easiest to start at the central node, and work towards the busy bead area. This helps determining where a ply layer starts and ends. Then the max angles for the plys can be set, and a multiplier allows the min angle of the ply. The materials for the tyres are already in the spreadsheet, and it is straight forwards to determine which material a ply layer consists of by looking at the material properties in the tgm, and then matching it in the spreadsheet material list. It took some time but honestly I was surprised how easy it was, as I thought it might have been impossible but maybe this will open up a whole new world of modding if we can get a few complete tgm spreadsheets circulating between modders with finsihed tyres ready to export.
Excuse my ignorance, but for anything more than editing realtime values by hand, isn't this how you would approach editing any existing tyres?
I don't think I've seen a mod that isn't a s397 generated tyre, only realtime parameters being played with. Do you happen to know of any? I didn't realise that the data required for the tgm spreadsheet is all there, exposed in the tgm file, and I gathered that that might be news to other modders.
I haven't tried to check, but for "making" tyres I'd either start designing from scratch or take some existing ones as a base. Just like doing car physics.
What about generating look up tables (all that stuff bellow "realtime" section), does spreadsheet do any of that ? And I also wonder if there are any modders that has developed proper knowledge, feel and handling of ttool.
It's not too bad honestly. Once you have a tgm generated in the spreadsheet, you load that tyre in ttool. That tgm contains the QSA model, which is the crazy detailed model that doesn't run in real time. Click 'show 3D' and you will see the qsa tyre. At this point if you click 'run physics' nothing will happen because that is for the realtime model specifically - so ignore the entire realtime section (top) The 'per interation' setting - set that to 20 or so, and the QSA model will run, and you can perform manual tests. At this point, ' you will be able to do some load tests, check out the contact patch behaviour, see how the tyre flexes, how pressure, camber and rotation effects everything. If you're not happy, make the changes in the tgm spreadsheet, click export, then click load again in ttool, redo some tests, did it work, rinse repeat ect. All this is quite fast - you don't have to wait very long for the manual tests to complete. Once you're happy, click 'run automated' tests. The automated tests are generated by the spreadsheet - you don't need to do much other than define max lateral and max longditudinal load, 2 rotational speeds and 2 temperatures. Then you can wait overnight. And you will be able to load the newly generated tgm, which now contains the lookup data for the realtime model. You can now perform realtime tests, and is even ready to be used on track.
That's what ttool does. The entire geometry and properties of the tyre is defined with text parameters, and ttool builds the lookup tables. This is covered in the original ttool documentation, and the blogs have more info and updates.
