Originally Posted by
Jeffrey McGrew
actually, I think that 'grid' isn't the shadow edges at all, it's the density of the Radiosity Grid showing.
Radiosity divides up your model by throwing a 'net' over the whole thing and then having the squares of that net talk to each other to figure out where the light is going within a space. Problems with this approach is twofold (and you see them both here): it takes a lot of time and never really gives you an accurate calculation as to where the light is going, and if the net's too big you see jagged edges in the shadows.
Unfortunately Accurender doesn't give you per-face Radiosity controls like other 3D software does, otherwise you could up the sampling on just the floor and get rid of those edges without slowing things down too much. But alas you can't do that.
The quality setting sets the size of the net, IIRC. But you're already topped that out.
So, instead, lessen the amount of area the 'net' is getting thrown on. Set up a 3D crop box in a generic 3D axon view to cut out just the area of the house you're rendering. Then go back to your Camera View, and set the Render Extents to that other view's crop box (it will show up on the list if you name the generic axon 3D view- I name them 'model crop for rendering' to make it simple).
What's probably happening is that the Radio solution is running over the whole of the floor and/or house, so it's setting the net way to big for what you're after...