i'm trying to make a shining/reflection material but i don't need to add any other object to the scene/layer, is there any way in order to do this? or should i add objects and then just hide them from the render?
Reference (as you can see, there are lights/reflections but not other objects)
Or, more realistic 'metal' like this?
In Cycle render engine you have an option to disable direct visibility of the objects to the camera.
Open Object Data tab and in Ray Visiility section disable this option on all the objects that you want to be invisible in render.
You can do the same with the background in World tab.
You probably need Background image. This can be anoying to set up. You need to look into something called Equirectangular maps. These are images that look all warped but will wrap around in a sphere around your entire scene. If you do not want to see this background, look to the scene/render area. Look for the "shading" area and find the bit that says "alpha" you can change it from "sky" to "transparent". This will give you the background image as a reflection but remove the background.
Alternatively, you can use texture mapping on the material. The coordinates should be "reflection". Although not as accurate, its very fast and less noisy.
