Updating the terrain after height change

I am trying to get the terrain to alter height during gameplay. It is very similar to the elliptical brush in the TerrainEditor. So similar, in fact, that I am pretty much just using the TerrainEditor to try to get it to do what I want. The problem I am having is that the in game map is not altering. Can someone tell me what I need to do to get the map to update. This is my code so far.

TerrainEditor * lTerrainEditor = new TerrainEditor();
    lTerrainEditor->attachTerrain(terrBlock);

    //**********************************************
    // find the weights for all the points that need to change
    // and change the height
    //**********************************************

    F32 a = 1 / (F32(radius));
    F32 b = 1 / (F32(radius));
    
    Point2I cPos;
    

    for(U32 x = 0; x < diameter; x++)
    {
        for(U32 y = 0; y < diameter; y++)
        {
            F32 xp = radius - x;
            F32 yp = radius - y;

            F32 factor = (a * a * xp * xp) + (b * b * yp * yp);
            if(factor > 1)
                continue;

            GridInfo info;
            lTerrainEditor->getGridInfo(Point2I((S32)(position->x + x - radius), (S32)(position->y + y - radius)), info);
            info.mWeight = filter.getValue(factor);

            info.mHeight = info.mHeight - radius * 0.5 * info.mWeight;

            // clamp it
            if(info.mHeight < 0.f)
                info.mHeight = 0.f;
            if(info.mHeight > 2047.f)
                info.mHeight = 2047.f;

            lTerrainEditor->setGridInfoHeight(info);

        }
    }

    // update the grid for the terrain
    lTerrainEditor->gridUpdateComplete();

I am stepping through the code and I know my TerrainBlock is getting initialized. My TerrainEditor seems fine and when I am getting the GridInfo it has valid information. I step through setGridHeight(info) and everything seems to be in order. It is just that when all is said and done, the map that I am playing on has not changed. Does something even higher level in the game process need to get called or triggered?