I want to render connecting pipes like in Thermal Dynamics, Industrial Craft, Mekanism etc., but it's hard. How can I do it?

Edited October 8, 20186 yr by TSEngineer

Afaik all of the mods you've listed use multipart models for their pipes, not TESRs.

Right, TESR's aren't necessary at all for pipe rendering (and will hurt your client-side performance if you have more than a few).  I'd also recommend taking a look at TheGreyGhost's examples here: https://github.com/TheGreyGhost/MinecraftByExample - in particular MBE05 covers dynamically rendering connections based on a block's neighbours.

TESRs are a lot worse for performance (they run every frame) than multipart models (they get computed every time a block update close to them happens) AND with TESRs you have to handle lighting etc. While with multipart models lighting gets handled automatically. You can also use a combination of multipart models and TESRs or Forge's Animation API to add other textures & effects. You might want to take a look at my mod which renders my energy cables with multipart models and renders electricity flowing with a TESR