I add an object to my scene, which already has several objects in it. I do a test render, and the new objects are not visible. The scene is set up such that the camera is viewing pretty directly in front of the object.
The first time this happened I realized that somehow the objects was not created quite where I thought it was, and was in fact, behind the camera. I brought if forward and it showed up.
When it happened again, I checked the object location, it was again behind the camera. I brought it forward, but still wasn't showing up in the render. I double checked the location, switching to side and top views to make sure it was where I thought it was. Still not showing up in the render. I then added another object, and that one does show up.
I am very confused.
the hairy scotsman
first off new objects appear at the cursor which due to an accidental LMB click be someplace unexpected.
Objects can not appear at render for various reasons;
In the Outliner check to see if it has been deselected for rendering.
Check you layers, each scene has twenty layers, although the default renderer captures all twenty, this can be easily changed.
Check your materials, some material settings (Cast Only for example) will cause an object to not be rendered.