Faster Iris Shadow Mapper

Faster Iris Shadow Mapper

Slightly improves the speed of Iris' shadow mapper. Built-in in Iris since Iris 1.11.2

by
419.3K Downloads
fabricforgeneoforgequiltoptimization
Configure a Compatible Minecraft Server

Screenshots

FISM logo
100 FPS vs 86 for default Iris

About this Mod

⚠️ This has been included in Iris 1.11.2, it is now only useful for older MC versions or for forks like oculus ⚠️

Faster Iris Shadow Mapping is a really lightweight mod that prevents unneeded things from rendering during the shadow pass.

This project does not replace Iris, both needs to be used at the same time for it to work.

This mod also works with oculus.

How it works

During the shadow pass, for opaque models, the color of the model won't have any visual change, a blue car and a red car both cast the same shadow, no matter their color.
So what this mod does is it prevents things like the text on signs, the banner patterns, the enchantment glint etc from rendering during the shadow pass.
It only improves performances when some of those are visibles.

Performance showcase

Small base in a flat world (26.1.2 - 1.0.0)

With / Without | 100FPS / 87FPS (avg) | 63FPS / 58 FPS (0.05% low)
With: 100FPS Without: 87FPS
  • +10% FPS

A lot of signs and banners (26.1.2 - 1.0.0)

With / Without | 15FPS / 9FPS (avg) | 10FPS / 1 FPS (0.05% low)
With: 15FPS Without: 9FP
  • +50% FPS on average
  • +1000% FPS on 0.05% low
  • The signs have text on them but on the other side

Modpacks

Feel free to use this mod in your modpacks without asking for permission.

Available Versions

Faster Iris Shadow Mapper 1.0.5release
MC 1.21, 1.21.1neoforge
June 21, 2026
Fancy World Animations 1.0.6release
MC 1.20.1fabric, quilt
June 21, 2026
Faster Iris Shadow Mapper 1.0.6release
MC 1.20.1forge, neoforge
June 21, 2026
Faster Iris Shadow Mapper 1.0.4release
MC 26.2fabric, quilt
June 19, 2026
Faster Iris Shadow Mapper 1.0.5release
MC 1.21, 1.21.1fabric, quilt
June 15, 2026

How to Install Faster Iris Shadow Mapper on Your Client

1

Install the Mod Loader Locally

Install fabric for your local Minecraft version.

2

Download the Matching File

Choose the Faster Iris Shadow Mapper file for fabric and Minecraft 26.2.

3

Install Mod

Place the .jar file in your local .minecraft/mods folder and restart Minecraft. No server-side installation is required.

Compatibility

Mod Loaders

fabricforgeneoforgequilt

Minecraft Versions

26.2, 26.1.2, 26.1.1 (+14 more)

Server-side

Unsupported

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Does Faster Iris Shadow Mapper need to be installed on the Minecraft server?

No. Modrinth marks Faster Iris Shadow Mapper as unsupported on the server side. Install it only in your local Minecraft mods folder. Your server can remain unchanged unless the mod page lists an additional dependency.

Which version and loader does Faster Iris Shadow Mapper require?

Use a file for fabric, forge, neoforge, quilt and your exact Minecraft version. Supported versions include 26.2, 26.1.2, 26.1.1. Files for different loaders are not interchangeable.

Faster Iris Shadow Mapper is not working – what should I check?

First check the Minecraft version, loader version and required dependencies. Put the .jar file in your local .minecraft/mods folder and remove older duplicates. Because this mod is client-side, adding server RAM will not fix it.

Minecraft Server for Your Group

Faster Iris Shadow Mapper stays on your client. Host a compatible world for your group.

Recommended RAM
4 GBfrom €5.2/mo
Minimum 3 GB | per 8 players
Create Server Now
Client Compatibility Guide
NVMe SSD Storage
DDoS Protection included

Details

License
MIT License
Server-side
Unsupported

Supported Versions

26.226.1.226.1.126.11.21.111.21.101.21.91.21.81.21.71.21.6+7 more