As of 9.16.2, this mod aims to be compatible with Iris shaders. In particular, the Rending Plinth's gateway block would otherwise be completely invisible due to the method used to render it. Sadly, there doesn't seem to be any automatic way to register blocks with all shaderpacks to have a specific render type. It therefore falls on you, the user, to tweak whatever shaderpack you're using to achieve the best results.

Alteratively, you can disable this compatibility feature in the client-side config file.

Known Shader Compatibility List

Below are which shaders perform well after tweaked for the 1.21 version (using Iris) or the 1.20 version (using Oculus). Though these mods are based on the same root, they actually behave somewhat differently here, so a shaderpack that is highly compatible with Reactive on one might not be on another.

Also, there are some shaderpacks that do not alter the graphics of the end portal beyond the Iris default -- those are listed as 'No Tweak Possible'. This means that they will work fine with Reactive, but the graphics of the Rending Plinth can't be improved by following this guide.

Iris (1.21.1)

Known Working:

Shader	Version Tested
Complimentary	r5.4
Photon	1.1
Rethinking Voxels	r0.1-beta6a
Super Duper Vanilla	1.3.5

No Tweak Possible:

Shader	Version Tested
SEUS Renewed	1.0.1
Sildur's Enhanced Default	1.171 Fancy
VanillaAA	1.3
Vanilla Plus	3.2

Known Not Working:

Shader	Version Tested	Issue
BSL	v8.4.01.2	End Portal material won't apply to Gateway

Oculus (1.20.1)

Known Working:

Shader	Version Tested
BSL	v8.4.01.2
Super Duper Vanilla	1.3.5

No Tweak Possible:

Shader	Version Tested
Vanilla Plus	3.2

Known Not Working:

Shader	Version Tested	Issue
Complimentary	r5.4	Gateway is invisible
Rethinking Voxels	r0.1-beta6a	Gateway is invisible
Photon	1.1	Gateway is invisible
SEUS Renewed	1.0.1	Gateway is invisible
Sildur's Enhanced Default	1.171 Fancy	Gateway is invisible
VanillaAA	1.3	Gateway is invisible

Instructions

1. Unzip the shaderpack

First, open your instance folder and navigate to instance/shaderpacks. Extract the zip file containing the shader you want to modify into a folder inside the instance/shaderpacks folder. Iris can open folders as easily as zip files, so you'll be able to use it even unzipped.

2. Open block.properties

This file may be in the root of the shaderpack, but will definitely be somewhere inside it. It's a text file -- you can open it in Notepad or equivalent.

3. Find minecraft:end_gateway or end_gateway and add reactive:gateway to the same section(s)

If there are multiple instances, this probably means that the file is using conditional sections for different Minecraft versions. You can either just add reactive:gateway to the section for the version you're playing or just add it everywhere. You might also take the time to add blocks from other mods to relevant categories as you see fit.

For example, in Complementary Remastered, the relevant line would look like this when you're done:

block.60025=end_portal end_gateway reactive:gateway

4. Save the file and reload the shaderpack

You can reload either by reloading into the entire world, or by using the debug command F3 + R. With any luck, the gateways above Rending Plinths should now look similar to End Gateways do in your shaderpack!