XYZ To UVW is also known as planar projection or flat mapping. This mapping type takes the coordinates in world or object space and uses them as UVW coordinates. For images, just the X and Y coordinates are relevant, which are mapped to U and V. In other words, the images use flat mapping projected along the Z-axis. XYZ To UVW results differ depending on whether it is applied to a Procedural texture or an imported texture.
Figure 1: XYZ To UVW projection applied to a box, cylinder, and sphere
Figure 2 shows the XYZ To UVW Projection applied to an OctaneRender® Checks texture. The XYZ To UVW node is further controlled by connecting a 3D Transform node to the XYZ Transformation input.
Figure 2: The XYZ to UVW Projection node connected to a Checks texture's Projection input