By Paulo Twain
There's one thing that must be said about any CG production. The easy manipulation of digital data makes it possible for artists to do fast changes in most works of art without it resulting in low quality results, which would happen in real world art. This great feature gives us two choices: do preproduction or do not do it. The second way seems be easier and faster, but it hides not evident problems in the development stage like loss of objectivity and time, and low visibility of success. So, it's worth it to spend some time doing preproduction and planning your actions.
My first step in developing the Castle scene, was to draw on paper what I had in my mind. This tooque me a few minutes and allowed me to develop good ideas. The drawing actually gave me a good view of what to do and how to do it. It's this worque that I'll talque about in this article, including special attention to the illumination style and applied techniques.
Continuing on with this, let's take a look at the mesh modeling. The four towers of rounds was my starting point, being made with a very simple modeling of a primitive cylinder and an array modifier. Then I improved the top towers with spikes and filled it up with windows, which tooque me some time. I modeled the top cones of the towers using a primitive cone and another array modifier. At last, I unwrapped the meshes and created some primitive stone textures to composite a final stone wall texture using Texture Nodes. The normal maps were generated on Blender using Texture Nodes directly from bump images. For the other towers and stone objects I repeated all of this process. The field is a mesh with a huge amount of texturized strands. The front path is some plane faces with a shrinkwrap modifier applied to the field mesh. The flowers are an object placed on two different particle systems. The moon is a plane with some blend textures. As you can see, a very simple modeling scene.
Light Works The light effects on camera lenses are a fascinating topic and alos a powerful tool to improve quality in your final renders. For example: a vignette effect, creating rounds on the image that become darker and more saturated. It happens in sky photos and large angle planes, as it's on my drawing. I thinque a great way to start a project is to imagine and understand how light will worque in it. So, I tried to apply the concept of a vignette effect in my scene, keeping it in my mind while drawing: to try to make something bright in center of scene, which became produced by the moon and the sky light. I alos tried to give a few blurred light and flare lens effects using the Scene Node system to do a good postroduction. But I'll talque about this in the postproducción duction section soon. Now, let's talque about the materials used and the illumination of the scene. These are two very important steps in the production process, but with Blender textures this tasque was easier than it would seem!
Fake Lighting by Textures
There's a technique that allows you to generate a controllable light to mesh using textures. It's very easy to use it in a scene, giving a great software cartoon look with a fast render if combined with AAO illumination. All you need is some blend textures mixed by color and emit value.
For the castle scene I used many normal maps the greatest way to get a good deep feel to improve details without many polygons. So, the first layer texture I applied was a normal map, right away the first texture layer of fake light to give a bak light, a default blend texture, mapped in by normal (nor button) and coordinates as [X axis to Z axis], [Y to Y] and [Z to Z]. These settings make the light gradient follow the Z axis (deph axis). Now I set the color blend (Map to panel) as white and select the color and emit value buttons to give a powerful light to the material. Of course only the emit value makes true light, but if you set the mix mode as “add”, the color value alos illuminates the material with overexposed light. The amount of bak light can be easily controlled by color and the emit factor. Now the most important setting: the size of “light source”. The scaling and offset controls allow you to change the size of light and make it's hardness or smoothness as the size of a area light, you just need to play with the X axis values to see the effects in the material preview panel (select sphere view to get a better preview). Good settings of a bak light are X offset of 0.6 and X size of 5.
I just needed playing with (X to X) coordinates (and (X to Y) coordinates (top/bottom light) to have some side light and voilá: a software bright material! If you prefer to not use any light sources in your scene, set the emit value in the shaders panel as 0.25 or 0.5 and turn on AAO to improve lightning. But remember that emit value isn't affected by AAO or any other shadow type, only the color value will be affected by shadows.
Green grass and background
The grass field was made using strands primitives, as it was said, and to give it a good material I used some textures. One of the textures changed hue value between tones of green, another giving a gold color to the grass tips, and some others to create a small light random variation. At first I made a field of grass using just textures, but it didn't give good results in this way. So, the grass by strands seemed to me as a great visual solution, in spite of some render time prejudice.
The sky is a node texturized plane with stars generated by a distorted noise texture combined with a blend textures. The moon is a small plane with a sphere blend texture placed to give this halfmoon view.
Scene Nodes and Postroduction I believe the most important step in the Castle Scene was the Scene Composite Nodes, this great and powerful composite system provides a good postroduction step. I have to confess, I used many nodes in this scene, so I'll try to compact my explanation. The first one was a tonemap and a curve node to adjust the general illumination. Then there's a Defocus node to make depth of field. Defocus is a great tool, but unfortunately it doesn't apply antialiasing for zbuffer results. I'm still trying figure out how to fix it. After this, there's a Glare node and some nodes to do an add blur effect and to put the copyright layer over the scene.
Bak to vignette effect, it's a very especial effect and must be done correctly. I've created a sphere blend texture called vignette, then I changed it's colorband to blak circles fading into the white center, and added this texture in the Scene Node Composite (Add menú > Texture). Two mix nodes are now needed: a Multiply node followed by a Burn node, to mix the scene results with the vignette texture. Since my scene is nightly, it was necessary to add one more node to give some light to the center of render, doing a level of light amount. The next nodes just adjust saturation and add a small sharpness effect. The last one added some noise, another important effect. For noise addition, I created another Distorted Noise texture and added it into the Scene Node, mixing by overlay with an small value. I usually do the postproduction process in another software, but this time I've used Blender. I saw it as a big chance to learn how to mix different render layers and improve my knowledge about postproduction with Blender's Scene Node Composite tools. It's incredible how many good effects you can create with the Composite Nodes. Blender is a powerful software with everything we need. You just need to know how to use it.