Here is an overview of the mental ray and iray features which were integrated in 3ds Max 2016.
NVIDIA Material Definition Language (MDL)
The Material Definition Language (MDL) is an NVIDIA initiative to standardize physically based material designs in a common format, see http://www.nvidia.com/MDL. mental ray for 3ds Max 2016 is capable of rendering pre-packaged MDL materials. We will create a dedicated blog post to explain how to enable MDL in 3ds Max 2016.
Light Importance Sampling (LIS)
The new Light Importance Sampling mechanism in mental ray allows to sample the whole set of lights as if it were one single light, placing more samples on the lights that contribute more to the part of the scene being rendered. It is an importance-driven mechanism that is controlled by a simple set of parameters. Both area and point lights are importance-sampled, and there is no fundamental change required in material and light shaders. This mechanism is typically useful in scenes with many lights, but can be beneficial also in other simpler cases.
Ambient Occlusion, GPU accelerated
mental ray offers a new, efficient, GPU accelerated “mr Ambient Occlusion” render element.
The “Max Distance” controls the maximum distance of occlusion probe rays (Note: Value 0 for “Max Distance” means infinite distance). “Falloff” controls how much the occlusion fades out with distance.
The mental ray and the iray renderers now offer the “Parametric” approximation method which can help to troubleshoot scenes where the “Length” method exhibits artifacts, for example scenes with very regular and flat geometry. This method is available from the “Render Setup/Renderer” tab and from the “Object Properties/mental ray” tab.
The parametric approximation method regularly subdivides each triangle of the surface. The “Subdivision Level” specifies how many times each input triangle should be subdivided. A higher “Subdivision Level” results in a higher triangle count. Each input triangle is subdivided into
4(Subdivision Level) triangles. Note: there is an internal limit of 8 million triangles per object.
The iray renderer offers a new helper object “iray Section”. The “iray Section” behaves similarly to the “Grid” helper and is used to cut off the geometry in the rendered image. Section planes can either cut off the geometry completely (so let the light in), or let the viewer take a peek inside, see “Clip Light” parameter. You can define up to 8 section planes.
The iray “Texture Compression” can save around 75% of texture memory on both CPU and GPU. This is enabled by default. See http://blog.irayrender.com/post/54506874080/saving-on-texture-memory for details, the level of compression exposed in 3ds Max 2016 is the “medium”.
Light Path Expressions Improvements
Light Path Expressions (LPEs) for iray have been extended to allow light-specific and object-specific paths.
Lights and objects need to be grouped into layers before they can be referenced in LPEs.
We will create a dedicated blogpost to explain this mechanism.
Irradiance Render Element
The iray renderer offers a new Render Element “iray: Irradiance”:
It is recommended to turn off tone mapping when computing irradiance. By default the irradiance buffer is converted to a heatmap, displaying the lux (or footcandle) values with false colors:
Auxiliary Buffers Render Elements: Alpha, Normal, Depth
The iray renderer also offers auxiliary buffers Render Elements (Alpha, Normal and Depth):
Here is for the tour of the new mental ray and iray features integrated in 3ds Max 2016.
Hope you will find this useful.