Interested in Modelica animation?

3D animation is an essential tool for developing and debugging physical systems because it allows developers to use their highly-trained eyes and experience of the physical world to look for modeling errors. Yet animation is overlooked by many Modelica tools; they may have a basic capability but most of their development/UX effort is elsewhere. The problem is twofold: experienced developers work on the needs of experienced users, and of the resources gap between solo/small team Modelica users and corporate / university research groups. Modelica By Example is a great resource, but only because Dr. Tiller decided to create it; it was not 'needed' or produced by any of the leading Modelica organizations, by those who determine tool development priorities.

I have been frustrated in making animations for the MonthlyMechanisms, dealing either with OMEdit's inability to display STLs and save animations (this was recorded by screencap) or the DLR's poor rendering. Other people have this problem as well.

What do you want in a Modelica animation tool?

My initial design is bare-bones: a post-simulation script taking the model and result files, producing an animation according to parameters. Rigid bodies will use the same shape= field to specify the shape, though allowing more advanced files like glTF. Initially, it will be restricted to models contained in a single file, as parsing a modelica package tree is tedious. Animation will be performed by three.js, with an optional output of the three.js scene JSON. The basic workflow will be an MIT-licensed Julia package, email me for translations into other languages.

How you can help: #

• what Modelica tool and scripting language do you prefer to use?
• what systems are you modeling, can you send me an example link?
• and, because the wheels need to turn, is your use commercial?

Please leave comments on GitHub.

Existing work: #

• I wrote an module for MAT.jl to read Modelica v4 .mat files
• MeshCat.jl - focused on creating Three.js viewers from Julia processes
• Modia3D - not there yet, cannot handle kinematic loops
• ?

— Ben Conrad

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