Describe the bug
Starting a game on the chess board drops fps to less than half with Iris shaders enabled.

To Reproduce
Steps to reproduce the behavior:

1. Enable Iris shaders
2. Place chess board
3. Start a game

Expected behavior
Minimal FPS loss

Screenshots

Debug crash log
crash-2025-06-04_12.49.54-client.txt

Additional context
Version 16.0.0 of my Tekxit 4 modpack.

This is because with shaders the render system is using the fallback / compat mode.
Essentially this is just vanilla rendering with nothing fancy going on, to allow for Iris / OptiFine to work with it.
Without shaders you get performance mode, which is what allows you to render endless pieces with minimal FPS loss.
In the current versions of the mod there is not really any way to avoid this, as Iris / OptiFine and their shaders aren't compatible with "core shaders" (rendering related stuff we used for optimization).

So this isn't really a bug, just a limitation of the current system.

BUT worry not! My friend and author of the chess rendering code (currently chess renderer v3), has been working on a new system for the library mod I'm making. I wont go into technical details because there is a lot to it, but basically with the new system we will make "chess renderer v4" which will come with even more performance for rendering without shaders AND with shader compatibility.

Here is an example of the queen model being rendered without shaders, this is 200k of them:

And here is an example of the queen model being rendered with shaders, this is around 20k from what I remember:

📝Note: In the images above FPS may look "low" at around 15 FPS, but keep in mind that these images are extreme stress tests, under normal conditions you wont be loading 200k or even 20k models at once. And with a more reasonable quantity the performance impact is nearly unnoticeable.

Now you may ask "when will this be ready", and to that I say "good question".
To keep it short the library is coming along nicely but still needs work, and I will take my time with it to ensure it is high quality.
I also plan to add/overhaul other features in Table Top Craft which might delay the update a bit further. So chess renderer v4 likely wont release in the "near future" but its on its way.

Hope this clarifies the situation and gives you some insight on the state of things! For now I recommend you keep chess boards to a minimum (while playing with shaders), to avoid the performance impact you noticed.

Interesting, well I'm glad there's a new renderer in the works, thank you for the detailed response and your time
Having board games within Minecraft is very cool and I love the mod

For now I guess I can add a tooltip to the game board in my next update to clear the game boards after playing a game

So a bit of a status update on chess renderer V4:

Still got some backend work to do for the system to make it a bit more reliable and work a bit better, as well as whatever else andrew wants to do before the next release

But TTC has been hooked up to the engine; which has pointed out some issues with the engine to me

Still no ETA, but shader performance will be quite good, and non-shader performance will also be dramatically better than it was in the previous version

I'm actually still not satisfied with the performance, but it'll do for now