As a Christmas present, we want to share with you the steps needed to create our Xmas2013 image in blender. This tutorial has it that you have a basic understanding of blender, how to create new objects and materials. We are going to explore how to use Particles to ramdomly populate a volume, create a shiny flake material, use DOF and compositing.
1. Create the object that you want to use as snow flakes. I imported some curves from Inkscape, converted them to Mesh, cleaned it a bit, extruded and polar arrayed [according to this tutorial (notice that I named the Empty so that it would later be used as a Focus)].
2. Create a Cube so that is represents the space which will be populated with our particles (snow flakes). I made it the shape of a truncatd pyramid so that would folow the camera perspective.
3. Create the particle system. I highlighted all the necessary steps, but I would like ot explain some of them. This system was created for animation, so it is normal to consider particles being created and moving around: that is way we have controls for Start frame and End frame. As we are creating a still image, we set these both to 1 and be sure to set your blender frame to 1 as well. [Emit From: Volume] makes it possible for the particles to be created inside the cube; otherwise, these would only be created on its surface.
4. Render and watch the effect. This is clearly a daylight, and we want to change that.
5. Change the World material to suit a more nightly effect. Notice that our flakes are lost in the night darkness. We will make them emit light.
6. Create the Emission material following the node setup in the image. These now glow in the night.
7. Create some DOF (Depth of Field) following the settings in the Camera tab.
8. Now its time for some compositing. This is the image before compositing. I will be moving the Viewer node to the right for you to grasp the effect of each node.
9. Color Correction: I made the Highlights and Midtones a bit more yellowish
10. Lens Distortion: This makes it possible to add Chromatic Aberration
11. Blur: We use this to creat the glowing effect
12. Color Mix, Add: We are now adding the glowing blur to the original image
13. Glare: This node creates some nive lens flare effects
14. Color Mix, Mix: We are now missing the Glare with our previous image
15. Ellipse Mask: This will be the gene of our vignette
16. Blur: By blurring the ellipse, we get a nice mask to Multiply our image and create the vignetting effect
17. Color Mix, Mulitply: Final image! Don't forget to add a Composite node. Then, head over to a UV/Image Editor, change to Viewer Node and hit F3.