With our project in the render stage we asked our lecturer Alec for some advice with how to go about rendering out our stuff, and he suggested breaking it up into layers including colour,light,Occlusion, specular and reflection passes.
This as a result would potentially cut down our render time and help us achieve the plastic/cartoony look we were going for.
Setting up Specific passes in maya:
Before I started looking into the juicy bits of the tutorial I wanted to remind myself how to set up specific render passes within maya.
For example to set up a colour pass, you would select the relevant layer, right click and select attributes.
Then under the layer attributes, open the ‘Render Pass options’ tab to reveal several options such as colour,shadow,specular,beauty and diffuse.
In this case I selected colour.
After reacquainting myself with the process I continued on with the tutorial to gain abetter understanding what we’d need to do when rendering out our stuff.
- The colour layer, It renders out the flat colours and textures within you scene, in this case Alec had included an ambient light, with it’s ambient shade value turned to to a value of zero. which gives the following result, flat colour, no shading.
- The light pass is similar to the colour pass, with the exception of the light source and the ’emit specular value turned off in the attribute editor. This will give us hard shadows to layer over our work as seen below.
- With the Occlusion pass, a new material was assigned to all the objects within the scene and a surface shader was applied to that material, after which a ambient occlusion node was plugged into the out colour attribute of the surface shader.
- If no bump or normal maps are being used within your scene the surface shader method proves to be quicker. For a high definition occlusion change the samples value to 100 or above.
- With the specular layer, a layer override was created in the colour attribute which was then assigned the colour black. This in turn will pick up the specular value from the render.
- The anisotropic material with give you a sharper highlight for a better effect. and the material reflectivity turned to zero.
With the reflections pass, the emit specular value was turned off on the light source and and a layer override was created for the the reflectivity value which had a value of 1 (all the way up).
I thought the tutorial was really useful, i’ve worked with render layers in the past but from taking notes on this I can see that there’s way more to learn when it comes to setting up pass layers in maya, i’m looking forward to sitting down and applying these techniques to my own work, hopefully cut down on those render times as well.
In the next tutorial, Alec went over the compositing process within after effects, taking the layers set up in maya and basically putting them together to create a final comp.
Comping: Method One
Colour layer – base layer, mode set to normal blending mode
Occlusion layer – set to multiply blending node (however multiply can give an undisired grainy look to you comp)
Reflection Layer – Set to screen blending mode, opacity to 40%
Specular layer – Set to screen blending mode, opacity to 75%
Light pass layer – Set to normal blending mode, 40%
Comping: Method Two
- Create a pre-comp for the ambient occlusion which includes the colour, light and occlusion passes.
Colour pass – normal blending mode
Occlusion pass – Multiply blending mode
Light pass – Add blend mode, 40 percent opacity
Although the end image is slightly brighter than what you you get in maya the get a more appealing shading result in the final outcome.