Are planes and quads interchangable ?

Noob question: If quads haved much less vertices and triangles than planes, can I always use them instead of planes ?

Of course you can as long as you’re not planning to alter the vertices so it’s not a plane anymore ^^. So your wouldn’t use a Quad as “cloth” since cloth needs vertices to work with.

Keep in mind thst the Quad’s surface points into the negative z direction (backwards) while the Plane’s surface points towards positive y direction (up axis, green). So you can’t simply exchange the mesh without rotating it the right way. Also a Plane has a size of 10x10 world units while a quad is 1x1 units large. So you have to adjust the scale as well if you want to replace a plane with a quad.

The built-in Quad mesh is a quite new “feature”. In the past there only was the Plane mesh.