I've noticed that when scaling up terrain decals, they appear to be getting clipped by the view near plane.
For example, add the following line of code to the Update() method in the Pathfind tutorial. Just after the decal.matrix.setPosDir(...) line.
Code:
decal.matrix.scaleOrn(32);
Then run the tutorial and click on the terrain to display the yellow star decal. Move the camera around and you'll see the decal getting clipped.
If you then change the scale so it only scales in the xz plane, the clipping goes away. Like this.
Code:
decal.matrix.scaleOrn(Vec(32,1,32));
However then the decal only applies to 1 unit (on the y-axis) of geometry. Try clicking on the rocks to see what I mean. You'll also notice it if you add a hill to the terrain.
Is there any way to scale a decal up to cover a large area of the terrain without clipping?