Enable 3D Item Models in Your World
Prerequisites
Before you can see the 3D item models from Just 3 D Stuffs, you need both the resource pack and the Hold My Items mod installed and active. The resource pack alone will not display 3D models in vanilla Minecraft.
Activating the Resource Pack
1. Open your world or create a new one with Hold My Items mod enabled
2. Press Esc to open the pause menu
3. Go to Options → Resource Packs
4. Find "Just 3 D Stuffs" in the available packs list on the left
5. Click the arrow button to move it to the active packs on the right
6. Close the menu and return to your world
You should now see 3D models when holding items in your hand. The models will be visible from any angle as you rotate your view, giving tools, food, and other items a solid, blocky appearance.
Troubleshooting
If you don't see 3D models, verify that Hold My Items is running. Check your mod loader's log for conflicts. You may need to adjust resource pack priority if other packs are interfering.