Some Success on the Horizon.
In tracking down the problem, I got a bit further but need assistance using MEL commands. In the previous posts I forgot to mention that batchRender with Maya Vector(plugIn) behaved exactlly like mentalRay(plugIn) in not-rendering-at-all.
Using MEL commands Maya Vector batch render works ok as long the command refers to the object (=ball) alone.
e.g.: batchRender ball;
Addressing the file by using the flag -f plus file name (=renderTest) has the same not-rendering-effect as clicking Render>Batch Render
e.g.: batchRender -f renderTest;
Using the same procedure with mentalRay addressing the object alone a very strange thing happens: batchRender is working, but it renders in Maya Software not in mentalRay
stating during rendering time- Result: rendering with mental ray ...
The rendered files are placed as Maya Software files under 'images' of current project with the current Render Global Settings for Maya Software. The folder currentProject/mentalRay/images stays empty.
Addressing the file instead of the object the render is finished after a few seconds without any result.
Using MEL commands for loading the plugIns makes no difference.
One solution I can think of to get around this problem is writing a MEL command to turn Render Current Frame, which works ok, into a command to render all the other frames as well. My MEL knowledge is too limited. Please help.
Many thanks