Irrlicht Engine

I am trying to come up with a way to highlight certain areas of a world object. Say you're walking around on a contour map, and suddenly you want to know how far you can reach or walk in one turn. So, a circular (or some shape) area of the ground beneath your feet is highlighted.

Looking at the API, my first thought is to add a texture of type EMT_TRANSPARENT_ADD_COLOR to the node's material channel 1. The problem I get here is that I want to be able to apply multiple highlights (say your buddy also wants to know how far he can reach), perhaps of different colors, etc. and it looks like there are only two material channels.

Any recommendations?

How about decals - a projected textured surface that sits above the normal surface, either geometrically, or using Depth Bias or Slope Scale Depth Bias.

If your ground is planar, applying decals is trivial.

well i think u mean tilebased 3d games right?

yeah i think he wants to project player markers on the ground, the markers being textures, its allot harder to do this by using textures on the old mesh just add new meshes (ground aligned polygons)