Does anyone have a good list of coefficient values for the properties of particular materials (pexiglass, aluminium, stainless steel, mild steel etc.) that actually works for BNG? A problem I've encountered modding existing mods is that the game engine doesn't do so well with real world values for highly rigid and thin objects and so its quite hard to fine tune beams without having the knowledge/prior experience of working with beamng's jbeam system before. I always wondered how you could even create an accurate functional yet alone crash model without accurate beam values readily available. How the beam-node structure is formed too and how it connects has a huge impact on how materials behave under strain e.g. if you used 8 connections per node, it has more rigidity than a node that has 6 or for example, and if you don't add a spacer support node, flat surfaces can kinda flop or cause beam damp oscillation/instabilities. Speaking of support nodes, there are several vehicles like the pigeon's door on the cargo box upfit where the author forgot to set the support node as a non-collidable node, and support nodes can cause additional problems if their weight is high enough. I understand that it's highly situational, for example you would need to apply a higher beamspring value for thicker components, but for models that use a wide variety of materials, this can get annoying. I'm new to this community, so I was wondering if anyone's already done the hard work and made a spreadsheet calculator for that sort of stuff already This is kinda important for me later because if I do eventually go along with making a new helicopter mod for BNG, the material values need to be accurate without the game engine breaking itself apart as there are very high torsional and compression loads, with a lot of dampening required and from what I've already noticed, dampening values are very sensitive and is very hard to fine tune. A lot of "spiking" visual issues also exist even in vanilla models because they aren't perfect - imo, no beam should ever be set to FLT_MAX either since that just causes problems under unusually high strain circumstances
Also, although unrelated, does anyone know any existing tools to help debug their tables other than this json5 validator and the built-in jbeam leak detector? The jbeam leak detector is extremely helpful but there's nothing equivalent for debugging json files (e.g. xyz.facilities.json which has to be made by hand it seems)
Well it doesn’t work like this, everything from structure, weight and the expected forces, will affect the values. Try to look at other vehicles and adjust from that. Test and change as needed. Sometimes you need to compromise on weight or stiffness of the structure or the overall deformation of the mesh. Best practice is to start with something existing and modify that, when you are more experienced try building up new jbeam by yourself. Best luck and fun, the community is behind you on the way to create your own content
I have thought about calculating some values for various materials, but there is so much more to it than just picking a beam spring value that I abandoned ship. You would have to do a series of calculations for every single beam to get the values and it would be a massive undertaking. It worked out better to just carefully place each beam and node so that they approximately mimic how a structure would react in real life and just tweak values from there. The beam and node structure isn't perfect, but it is a dramatic simplification that does a good job of matching realty if done right. I might end up doing some calculations for curiosity now though.
