Here are my settings:
Possible causes for blank output on rendering
Please follow the links in blue for further details
1 - No Surfaces
- Make sure Surfaces is enabled otherwise Cycles has no geometry to render
2 - Objects have been disabled for rendering
- Objects might have been disabled for rendering in the Outliner. To fix enable the camera icon in the outliner
- The Eye icon is to toggle object visibility on the 3D viewport.
- The Arrow Icon toggles selectability.
- The Camera Icon toggles Rendering.
3 - Lights
- There are no lights in scene.
To fix add some lights.
Lights are set at 0 power. To fix change the values to a higher number.
Lights have been disabled for rendering.
Enable the camera icon in outliner window.
Lights have incorrect Shader Nodes with incoherent output
4 - Strips on the VSE
- There are strips present in VSE and the Sequencer box enabled in Post-Processing. The VSE takes precedence over scene rendering.
To fix clear the strips on the VSE or disable the Sequencer box.
5 - Object or camera are in a different render layer
To fix include the layer where the objects are as part of the render layers.
6 - Camera is blocked
The camera might be behind a wall or another object
An object in front of the camera might be restricted from viewport display, making the issue not apparent in the viewport or render preview.
Camera clipping might prevent surfaces very close to the camera from showing in the viewport but still prevent it from rendering correctly
If Backface Culling is enabled in the viewport surfaces might not block view in the viewport but still show in render.
7 - Camera is set incorrectly
The rendered image is that of the active camera's view. Not necessarily the view you have active in the 3d vieport. Press Numpad 0 to show camera view.
Active camera is aiming in a different direction.
- Wrong camera being rendered.
You can have multiple cameras in the scene, but only one can be set as the active camera for rendering. Check that you are using the correct one.
In the Properties Window you can determine which camera is the active one
Or select the camera you want to make active in the viewport and press Ctrl+Numpad 0 to select the active camera.
8 - Object as Camera
- An object in the scene has been set as camera.
To fix set the active camera back to an actual camera object.
9 - Output node disconnected
- Output node in compositor might be disconnected. The composite node is the final output (not the viewer node).
10 - Wrong exposure
- Film exposure is set to 0 (Cycles) Unless you have a good reason to change it. This should be set at 1.
11 - Clip Distance
Make sure that you set the clip start and clip end so that the camera can see within a distance range that encompasses the scene. Geometry that is too close or further away than the set parameters will not render.
If your scene is too large or too small, if the scene is not within the range defined by the clip distance, then the camera will not "see the scene". Enable Display Limits on the camera to visualize the clip range.
12 - The scene is completely out of focus (blurry)
- Focus for the camera set to 0 and lens aperture (f-stop) is set to a low value.
The scene is so out of focus that you only see gray or some color that is predominant in the scene.
To fix, change the distance value to the actual distance form the camera to your object, and maybe try a higher number for the f-stop.
To find where your camera is focusing you can enable display->Limits. If you move the focus you'll see a cross mark that indicates where the focus point is:
A trick you can do is use an empty. Move the empty to the place you want the camera to focus on and select the empty (or any other object as the focus target).
Also read also this related post: Why does my object not sow up ?
aha.....tracked it down to the fact that when I was messing about with the mist with the compositor nodes I had left the use nodes and back drop buttons selected .....as there was no longer anything to 'composite' there was no longer anything to output I presume.....anyway sorted now. Another 3 hours of misery lol.