Triplanar Projection (triplanar projection / triplanar) is a technical term that is extremely important in the rendering and optimization of game graphics (technical art). A special shader technology that does not require UV expansion, completely ignoring the UV coordinates of the 3D model, and automatically composing textures by projecting them from three directions: top, side, and front in world space.
Real-world analogy: Technology for projecting patterns using a projector from three directions: front, back, left, right, and top and bottom on complex-shaped clay works
Triplanar projection is a technology that beautifully projects rock patterns from three projectors (top, side, and front) all at once, no matter how distorted and complex a lump of clay (3D mesh) is, without any UV development, and gently blends the overlapping boundaries.'' No matter how hard you stretch or transform the object, the projected pattern always fits neatly into the world space, so there are no stretching or texture seams, and an ultra-high-quality background is automatically completed.
Illustration: Triplanar Projection (Triplanar projection / An infographic that clearly illustrates the basic processing flow and mechanism of Triplanar) in Japanese.
Detailed mechanism and operating principle
Use the "Triplanar" node in Shader Graph to project and automatically blend and paste the same texture evenly from the three directions of the X, Y, and Z axes, depending on the object's orientation (normal).