Unfortunately I don't think that 's possible in 3D Rad. In Unity you can have the objects on different layers, therefore the cameras can render only a certain layer. But in 3D Rad there isn't really a way to separate the objects in terms of rendering.
If anyone has a solution, I'd be happy to hear it.
If you wanted both on screen at once, the camera viewport height and width are your friends here. Set them to something like 0.5 instead of 1.0 and you can have them side by side. Otherwise you'll need to cycle through them if you wanted a full-screen view. I'd personally use something like a timer set to 5 second intervals or a simple script.
thanks ninko I think power supersport is right. Switching camera and setting height, width can be done but my question is Overlaying camera2 on camera1 or vice versa. Is it possible. How it can be done? Or can it be done using shader
As ninkeo says.. what you want is possible so to speak if the main or first camera is set to less than 1 say 0.5 for both height & width then the second camera is left as full screen, then "some" objects like sprites do support displaying in specific cameras only by joining them in the list editor to one camera only.. this has the effect of PIP TV type display where one camera overlays the other as a smaller window.. not all objects support separate camera deisplay options... the best idea is to try this... i've never tried to use background images with transparency which mite help in this process... it really depends on what your specifically trying to do.. just saying overlay cameras doesn't describe what you want quiet enough.. Also you caant switch cameras from front to back, 3drad only allows you to turn on/or off given cameras, the display order is controlled by 3drad and the order they are added to the liste editor.. you could simulate the effect by using say extra cameras setup oposite to the first then switching them on off... but it still comes down to the "overlay" and what exactly you want to happen.
You can LOD skinMeshes in 3D Rad by utilizing the frame-by-frame animation. You just have each LOD as a different frame, and then you change the frame based on the distance of the camera to the object.
But, as for that many grass instances I don't think so. It would be impossible to reproduce the effect over that many objects without serious performance cost, as 3D Rad isn't built with instancing in mind.