The Default 3D Resource Pack 1.12.2/1.12.1 is a unique texture pack that comes with simple textures for a basical appearance of Minecraft. The custom 3D Resource Pack supports Minecraft Version 1.12.2/1.12.1/1.12/1.11.2/1.10.2, 1.10, 1.9.4 and most older versions. It changes the look of several ugly blocks to a more realistic 3D view. You will be pleased with a very realistic 3D look of many blocks. However, for significant higher fps-rates we recommend using Resource Packs in combination with Optifine. If you like the Default 3D pack you might also like the Basical Resource Pack.
Default 3D Resource Pack 1.12.2/1.12.1/1.11.2/1.10.2 Resource Pack Installation Guide
We recommend the 3/4-step installation below!
2. Run Minecraft.
3. Navigate from “options” > “Resource Packs” > “Open resource packs folder”.
5. Drag and drop the Default 3D Resource Pack (.zip file) into the folder that just opened.
If you don’t want/need to install Optifine just don’t do it.