[vtkusers] performance of on- and off- screen rendering

[N. Yang]

Dear all,

i am running some tests on the performance of vtk's on-screen and
off-screen rendering with Java, in terms of rendering time and program
execution time, i found out off-screen rendering is even faster than on
screen rendering, sometimes even doubled(with the same hardware
configuration and parameter setting), is this reasonable or not? the
off-screen rendering library in use is Mesa-5.0.2. any idea?

regards

Yang