Shadows on my objects is too shorts

What i did wrong?


FarPlane:=30000;
....
TV.SetShadowMandatory(true);
TV.SetShadowParameters(Global.RGBA(0,0,0,1),FarPlane/2);
.....
mesh.Optimize;
mesh.ComputeNormals;
mesh.SetShadowCast(true,1,-1);
....
render loop:
for n:=1 to mechCount do
begin
mesh[n].RenderShadow;
end;
Global.FinalizeShadows;
...