Today, I embark the journey of Arnold Rendering.
What is Arnold?
* Arnold is an advanced Monte Carlo ray tracing rendering built for the demands of feature-length animated and visual effects film. Originally, co-developed with Sony Pictures Imageworks, Arnold is now used at over 250 studios world wide.
- FRAME STORE
- THE MILL
- DIGIC PICTURES
Arnold was the primary renderer on dozens of films from Monster House andCloudy with a Chance of Meatballs to Pacific Rim and Award-Winner Gravity.
This is an example of Diffuse Noise produced in Arnold Renderer.
In an example from Solid Angle, this example is labelled as sample 3: (it reads as follows) Increasing this value gives cleaner GI (which basically means:Global Illumination) which diffuses the results.
To understand where noise comes from: We trace a light ray into a specified location, this is what the diffused shader ‘sees’. To find the light that is reflected from this surface, we need to find the average colour from all of these pixels.
Here is a very detailed example of how to effectively understand diffused lighting. This method is not just used in Arnold, diffused light has been experimented with throughout the history of photography.
This image above shows that process of diffused lighting. (Pretty sweet!)
Here is an example of how to produce this method using a DSRL camera. Arranging the light source, and adding light sources plays off on creating a effectively stimulating image.
Glossy controls the number of rays fired when computing the reflected indirect-radiance integrated over the hemisphere weighted by a specular BRDF (which basically mean: Birdirectional Reflectance Distribution Function).
Walt Disney Animation have their own BRDF Explorer; it can load and plot analytic BRDF functions (coded as functions in OpenGL’s GLSL shader language), measured material data from the MERL database, and anisotropic measured material data from MIT CSAIL. Graphs and visualizations update in realtime as parameters are changed, making it a useful tool for evaluating and understanding different BRDFs (and other component functions).
To explain further what glossary can do here is an image below to demonstrate this effect.
SSS (Sub-Surface Scattering)
This value controls the number of lighting samples (direct and indirect) that will be taken to estimate lighting within a radius of the point being shaded. Higher values produce a cleaner solution, but will take longer to render.
(above are 2 samples of this method, found on the Solid Angle website)
Volume Indirect controls the number of sample rays that get fired to compute indirect lighting of the volume. Like the other sampling rate controls (Camera, light samples, diffuse samples, etc), the number of actual samples is squared, so a setting of 3 fires 3×3=9 rays. Setting it to 0 turns off indirect lighting of the volume (which is the default). Note that indirect volume lighting is tied to the ‘Diffuse’ render option and therefore there must be at least 1 Diffuse bounce for indirect lighting to be computed.
Sample 1: Volume Indirect Sample 0 – No Indirect volume lighting
Sample 2: Volume Indirect Samples 1 – volume has indirect lighting but needs more samples.
Sample 3: Volume Indirect Samples 4 – Increasing the samples reduces the noise.
(above are 3 samples of the method, found on Solid Angle website)
Maya Class: Arnold Render Attempt 1
Here is an example of my very first attempt at tackling Arnold. Once I got into it, I soon discovered how beautifully this software renders. I had previously tried mental ray – Arnold is way better and I will enjoy playing with it further.