Rendering is the making of the final still image or animation - it can be very professional-looking and realistic, with shadows, reflections, textures and transparency like this render of Suzanne, Blender's mascot.
Rendering is very computation intensive - this is especially true of animations. A 10 second animation, for example, with 25 frames per second (still images per second) would contain 250 images, and each frame might take several seconds to compute, so the rendering of such an animation might take several minutes. Rendering a full-length movie might keep a powerful computer busy all night! Once the animation is done, however, it should run very smoothly - 25 frames per second is same as the frame rate used by European televisions.
Because rendering is so computation-intensive, one does not normally do rendering in real time while working in Blender, though one can do so by choosing 'rendered' as the 3D window display method instead of solid, textured, material etc.
To control the rendering process, click the render button (left) in the properties window. Here (right) are the most important settings:
Whether you are rendering a still image or a movie, there are some key concepts that will control the quality of the rendered image or movie:
- One is the resolution, or the number of pixels in the image. by default this will be 50% (both horitatanly and vertically) of the standard 'high definition (HD) resolution of 1920x1080 pixels. The default is set to 50% so that the renders do not take too long - the assumption is that you will set the render to be 100% of HD resolution when you are ready to make the final image.
- Another key concept is sampling - the higher the number of samples the higher the quality of the render, but at the cost of longer rendering times. You can set the number of samples separately for previewing (when you see when you choose the rendered display method for the 3D window) and for the final render (when you press F12). The default settings for (in the Sampling section of the render panel) are fine for most work, but you may want want to decrease the sampling numbers if renders seem to take too long, or increase them if your image seems 'dirty' with lots of light or dark colored dots that should not be there -this is called 'visual noise'.
- The extreme example of visual noise is very bright white dots called 'fireflies' which tend to appear if your scene has highly reflective surfaces (glossy or mirror). You can try to reduce the number of fireflies by setting non-zero 'clamping' values in the render panel - experiment to see what works, but be aware that clamping also has a price in that it makes the image less sharp.
Rendering a still image
Clicking the 'Image' button in the render panel or pressing F12 or choosing Render>Render Image renders a still image of whatever the active camera sees. The rendered still image can be hidden by pressing F11.
The size of the rendered image is set by adjusting the X and Y values (1920 x 1080 is the resolution of HD video). If you are not yet ready to do your final, finished render and just want a small, quick low-quality render then set the percentage to less than 100%.
Rendering a still image does not save it to your hard disk. To save the rendered image to your hard disk choose Image > Save As in the render window then specify a file type in the 'Save as' section (bottom right) choose a location, give a file name (if you don't include the extension it will be added automatically) then press the 'Save As' button. It is also possible to specify the desired file type before you do the render by setting in the Output section of the Render panel of the Properties window:
Rendering an animation
Clicking the 'Animation' button in the render panel or pressing Ctrl+F12 or choosing Render>Render Animation will cause an animation to be rendered - this can take many seconds, minutes or hours according to how long the animation will last and how big it is.
As previously mentioned, the dimensions of the animation can be set in the render panel and it is possible to render at a percentage of less than 100% if you want a quick, lower quality render because you are not yet ready to make the final high quality version. Before doing the rendering, be sure to set the Output file format to a movie format and not to a still image format such as PNG which is probably the default. A good choice would be AVI JPEG since this is a compressed format that should be playable in standard players such as Windows Media Player. If you leave the file format as a still image format such as PNG then you will get hundreds of individual files rather than a single movie file. Note that animation renders ARE always saved to your hard disk, unlike renders of still images, so be sure to set the folder name (/tmp\ by default) to a folder you have access to. If you leave the default folder as '/tmp\' then Blender will save to a folder called 'tmp' on your C drive (it will create this folder if it does not exist). It's probably best to set the folder name to // which means Blender should save the movie file in the same folder that the Blend file is located in.
When the render terminates (after several minutes, probably) you should find that a movie file has been created in your chosen folder. Double-clicking this file should open it in the associated player - the FLV player is well-known for good reason.