Installation guide to install Optimum Realism on Minecraft Java Edition with compatible shaders:-

Prerequisites:-

1. Optifine

2. Minecraft Java Edition(1.15+)

3. Java

4. Winrar

Most people have Java already installed on their computers, you can check if Java is installed on your PC by searching for Java on the search bar on Windows and it should show up. If you do not have it, you can go here and download it.

Optifine is an fps boost mod and this mod supports shaders, which Optimum Realism uses. You can download it from here. Once downloaded, simply click on the Jar file, this jar file should be clickable if Java was installed properly on your PC. Next, install it, and it may tell you to run Minecraft once so it could detect it and install itself.

Most shaders and resource packs come in archived forms, and this is mostly not a problem. For some of them, they require you to extract them. Optimum Realism does not require you to extract any files, however, it may in the future. You can download it here.

You need to run Optimum Realism with supported shaders to enjoy it at its maximum potential. Shaders like SEUS PTGI and Kappa are recommended, if you do not have a device that can run them at decent fps, you can opt to use a more lightweight shader such as BSL, but it may not have the best quality when compared to other shaders. Once you install it, simply cut it, then press cntrl + r, and type %appdata%, this will lead you to your roaming app data folder. Click on .minecraft and then paste it in a folder called "shaderpacks" if there's no folder like that, create one. 

Next, install Optimum Realism from either Gumroad or Patreon, or the demo versions from PlanetMinecraft or Curseforge. There are two variants available for the Java Edition version of Optimum Realism, LabPBR and OldPBR. Most shaders that or either updated recently or are new overall usually have LabPBR as their default format. OldPBR as the name suggests was an older PBR format that is still used by some popular shaders like Sonic Ether's Unbelievable Shaders and so on. 

Now as mentioned before, again press win+ r and type %appdata% this time go to the resource packs folder and paste Optimum Realism there.

Now, open Minecraft and go to video settings>resourcepacks and select Optimum Realism and load. Then, go to video settings>shaderpacks and load the shader you installed now. You've been provided with a graphical guide as well as the best settings for the Kappa Shader and SEUS PTGI HRR 2.1/3 below, however, you're not limited to these settings, you can experiment with them on your own depending upon the quality you want and the fps you'd like to have. You could also increase the sample rate to 256 to gain the best quality possible. (Change the texture resolution based on the resolution you downloaded on SEUS PTGI HRR 2.1/3)

Installation guide to install Optimum Realism on Minecraft Java Edition with compatible shaders:-

Prerequisites:-

1. Iris

2. Fabric

3. Minecraft Java Edition(1.15+)

4. Java

5. Winrar

Most people have Java already installed on their computers, you can check if Java is installed on your PC by searching for Java on the search bar on Windows and it should show up. If you do not have it, you can go here and download it.

Iris is an fps boost mod and this mod supports shaders, which Optimum Realism uses. Optimum Realism is a PBR & POM-enabled resource pack, the current release of Iris does not support this, the PBR version of Iris is currently on BETA and hence it's only available at their discord server. Click here to join it. Go to #public-test-builds to download it. Please read carefully. Once downloaded, press windows + r, then type in %appdata% it will lead you to your current profile's app data, there click on .minecraft and paste it inside the mods folder.

Fabric is a launcher that Iris currently supports, in order to play Optimum Realism with iris, you need to download the fabric launcher. You can go here and download it. Click on download universal jar and then open it, click on the latest launcher version and the current Minecraft version you want to download it for. You can also install some other mods with Iris to obtain more fps. Please make sure to match the versions correctly. Mods in bold are compulsory to download for Optimum Realism to work with Iris. You need to place these mods in the mod folder too.

• Sodium

• Dynamic FPS

• Phosphor or Starlight

• Ferrite core

• Lazy DFU

• Lithium

• Entity Culling

• Continuity

• Indium

You also need to make sure that you enable the Continuity mod by placing the two in-built resource pack by the Continuity mod below Optimum Realism in the resource packs menu.

Most shaders and resource packs come in archived forms, and this is mostly not a problem. For some of them, they require you to extract them. Optimum Realism does not require you to extract any files, however, it may in the future. You can download it here.

You need to run Optimum Realism with supported shaders to enjoy it at its maximum potential. Shaders like SEUS PTGI and Kappa(not supported with Iris) are recommended, if you do not have a device that can run them at decent fps, you can opt to use a more lightweight shader such as BSL, but it may not have the best quality when compared to other shaders. Once you install it, simply cut it, then press windows + r, and type %appdata%, this will lead you to your roaming app data folder. Click on .minecraft and then paste it in a folder called "shaderpacks" if there's no folder like that, create one. 

Next, install Optimum Realism from either Gumroad or Patreon, or the demo versions from PlanetMinecraft or Curseforge. There are two variants available for the Java Edition version of Optimum Realism, LabPBR and OldPBR. Most shaders that or either updated recently or are new overall usually have LabPBR as their default format. OldPBR as the name suggests was an older PBR format that is still used by some popular shaders like Sonic Ether's Unbelievable Shaders and so on. 

Now as mentioned before, again press win+ r and type %appdata% this time go to the resource packs folder and paste Optimum Realism there.

Now, open Minecraft and go to video settings>resourcepacks and select Optimum Realism and load. Then, go to video settings>shaderpacks and load the shader you installed now. You've been provided with a graphical guide as well as the best settings for the Kappa Shader and SEUS PTGI HRR 2.1/3 below, however, you're not limited to these settings, you can experiment with them on your own depending upon the quality you want and the fps you'd like to have. You could also increase the sample rate to 256 to gain the best quality possible. (Change the texture resolution based on the resolution you downloaded on SEUS PTGI HRR 2.1/3)

*Images were clicked using Optifine mod

Installation guide to install Optimum Realism on Minecraft Pocket Edition with shaders

Prerequisites:-

1. Minecraft Pocket Edition(1.16+)

2. Nori Shaders

3. A high-end phone

Optimum Realism was just recently made compatible to the Pocket Edition of Minecraft, which means you can play Optimum Realism on your mobile devices, remember Optimum Realism would require a high end mobile device. This version of Optimum Realism is extremely experimental and is not meant for casual gameplay. There are a lot of blocks that could not be made compatible and all models used in Optimum Realism Java Edition are not currently supported on the Pocket Edition at all.  It was an extremely lengthy process to make Optimum Realism compatible with Pocket Edition, as it brought many technical difficulties which had to be overcome.

To enable PBR & POM on Optimum Realism, you'd require Nori Shaders. 

Click on Nori PBR Base and download, next go to the Nori shaders itself and download that.

Download(here) - If you're on an android phone, click on the three dots on chrome, and select desktop site, then you'll see an option to download the code as zip, download it. Then extract and open and move the inner folder to your resourcepacks folder, which can be located by going to your internal storage - /storage/emulated/0/Android/data/com.mojang.minecraftpe/files/games/com.mojang/resource_packs (Android)

Now make sure to put them in this order in-game:-

1) Optimum Realism

2) PBR Base Pack

3) Nori Shaders