In this lesson we learned about aov layered rendering compositing.
This layering is the layering of objects, such as dividing a scene into independent layers, such as the character into a layer, the background into a layer, so that when rendering people the background is not rendered, the camera does not move, then sometimes you can only render a frame of the background, saving rendering time, aov layering is the channel layering, such as an object channel into a light layer color layer reflective layer diffuse reflection layer, and so on, and then use nuke compositing, multi-channel compositing is also called depth compositing.
Z channel is generally used to do the scene of the air fog and depth of field.
Ao, meaning environmental masking, is used to superimpose the shadows generated by the object and object contact, increasing the sense of volume.
Coat, varnish layer, is the second layer of material highlights, generally like celadon, such a glazed material will have this, and car paint also have.
diffuse, this is a color layer with light information, without any material other than color in it.
direct, this is the direct light layer, is based on the scene inside the light, calculate the effect of direct irradiation out, did not calculate the effect of photon bounce produced.
emission, this is the direct translation of the meaning, self-luminous, this channel will be the scene on the self-luminous parameters of the material extracted. Easy to adjust the content related to self-illumination later.
indirect, with the above description of direct, this channel is Arnold calculated according to the light of the photon bounce effect, that is, indirect lighting, like a sunlight, shining into the house, the house is not illuminated in places will also light, which is the photon bounce and indirect lighting.
motionvecto, because the scene is not animated, so use a small ball with animation to do the case. motionvector, motion vector, used to do the motion blur effect later.
opacity, this is the transparency channel, there are transparent properties will be raised to facilitate the control of transparent materials.
specular, highlight layer, used to adjust the intensity of the highlights of the Aov layer later.
sss, when an object has a subsurface, epidermal material, this channel can be convenient to adjust the size of the SSS later.
Transmission, the refraction layer, similar to water, glass and other such materials with refraction properties, this channel is convenient to adjust the size of refraction and other properties. Finally, when outputting Aov, we choose the material content according to the file, for example: there is no glass in the scene with refraction material, then transmission is not output. And so on, choose what you or the downstream department needs most, so that you can reduce the rendering time and improve efficiency.
In this class, we also learned about relight, the basic principle of which is to first model the real scene to create a digital scene. Then we take points in different parts of the real scene, and each point takes an omnidirectional cubemap, through which we can derive the lighting response of each point in the scene and apply it to the digital scene. Finally, you can move the light source randomly and get a rendering that looks fine. In my understanding, this is more like a 2.5d technique. Here are the four methods of relight.