Rendering / Advanced Render 3

New Render Settings

Anyone who had upgraded to R11 has likely found out that the new Advanced Render 3 Module is really a great improvement and is easy to work with. The GI (Global Illumination) engine has been rewritten completely from the ground up. While the new interface for render settings was a bit confusing at first, once you are used to the layout, you will find that like the rest of C4D, it´s pretty easy to use. For more experienced users there are additional settings to optimize your render times and render quality . In the image below you can see the new render settings panel and layout.

New Render Settings

The Output page of the render settings has been completely redone with the resolutions being organized into specific media presets. In the image below you can see the new Screen resolution presets.

Output Page Resolution Settings

To find the new options including GI settings and caustics, just expand the list under Effect... in the render settings.

Effects Menu - GI, Caustics etc

Standard Render Engine - Speed Improvements

If you´re rendering without GI you should notice a significant reduction in render times. Below is the same scene rendering in R10.5 and R11 along with the render times. As you can see, just a over a minute difference in render time between them so close to 100% render speed improvement in this example which I found to be a very typical render speed improvement. We give MAXON top marks for this.


Release 10.5 - Click for a larger view	Release 11 - Click for a larger view

Realistic looking glass using Absorption

Glass rendering has been significantly enhanced in R11. Not only does glass render much more accurately it also renders much quicker as well. The image below shows the new options in the transparency channel compared to R10.5

Transparency New Settings

New options are:

Total Internal Reflections - Previously called Fresnel (the S is not pronounced). This has been enhanced to work better.
Exit Reflections- These can now be disabled. The image below taken from the R11 documentation shows the top image with exit reflections enabled and the bottom image with them disabled. The enabled option is technically correct but the disabled one is often considered to be more visually appealing.

Exit Reflections can be disabled

Absorption Color - When you look through a pane of glass at right angles the glass is more or less completely transparent as at this angle the glass has least thickness. However when you look at the edge of a pane of glass where its thickness in relation to our eye is a lot thicker it will usually have a very noticeable green or blue colour. This is what Absorption Colour simulates. Rather than colouring the glass say green (which you can still do) you can leave it at the default white colour. By using a green colour as the Absorption colour we can get the green colour when we look at thicker areas of glass. You will see this effect in things like glass tumblers where the glass is tinted. The image below is a photograph of a tinted glass dessert bowl. The glass is all the same colour but the thicker base has a noticeably different colour.

Photo of Glass Dessert Bowl

Let´s try and duplicate the glass bowl by modelling it and applying a glass material. The image on the left is Release 10.5 and the image on the right is R11 where I have used the new Absorption Colour option. For the R10.5 version I had to play around with the transparency colour settings to try and get the right glass colour. Getting the results that you want with Release 11 were much easier to achieve plus of course much more accurate. Click on the images for a larger version.


R10.5 - Click image for larger version	R11.0 - Click image for larger version

As you can see, the R11 glass duplicates the way the glass behaves in the photo more accurately. The GI render is also much cleaner than the R10.5 render. The render time for Release 11 was 5 minutes 2 seconds and the Release 10.5 render was 13 minutes 54 seconds making the R11 render more than 2 and a half times quicker. Very impressive!! The white material applied to the ground plane by the way isn´t meant to be totally smooth. The material has the bump channel enabled with a little bit of noise. It also has 2% reflection and the specular channel is enabled.

Absorption Distance - This is used in conjunction with Absorption Colour. Lower values have the effect of making the colour closer to the Absorption colour and higher values have the colour closer to the colour defined by the colour settings above in the Transparency channel. The documentation describes it as: Use this setting to define the distance rays of light have to travel before Absorption Color replaces Color. The effect of using a higher distance on the dessert bowl is that the glass loses the tint and looks more like the 10.5 render. I found I had to experiment with several distances to get the result that I was happy with.
Blurriness - Dispersion is now called Blurriness.

In addition to the Transparency Channel enhancements the Reflection channel now has a new Additive option. The documentation describes it : This functionality (by default disabled; for reasons of compatibility it is automatically enabled when loading scenes from previous versions of C4D) makes objects´ reflections more realistic. In reality, the more reflective a surface the less of this surface´s color (material´s Color channel)) will come through. To put it briefly: More realistic rendering results if this option is disabled. I tried rendering the glass bowl with this option enabled and disabled. I couldn´t really notice much difference. Perhaps in different situations things would be different.

Global Illumination Enhancements

The Global Illumination settings in the new module allows for better use of multi-core processors and multi-threading. You will now see stochastic samples calculated, followed by a bucket render which calculates your irradiance cache and a final render that you are used to seeing in CINEMA 4D. These passes calculate your settings for samples, interpolation method, smoothing, oversampling and more. The end result is render quality is greatly improved. In just a few clicks you are now able to render out scenes with virtually no artifacts and smudging which is a terrific improvement.

Another change in the Advanced Render module is the support for RenderMan-compliant rendering engines. Settings can be selected in Render Options. For the Mac, you have a choice of Pixar´s PRMan and 3Delight as well. You can access the setup for the external renderer from within CINEMA 4D´s layout.

Let´s have a look how the new GI looks compared to earlier versions of CINEMA 4D. The 2 images below show the same image rendered in R10.5 and R11. Clearly the R11 render looks a lot cleaner but note the increased time. This seems to confirm what many people have been reporting in the forums. That is, R11 GI renders look a lot better but in many cases the render takes longer. There are however a lot more settings than previously so it is possible to reduce render times somewhat.


Release 10.5 - Click for a larger view	Release 11 - Click for a larger view

Here are some comparison renders between AR3 and the just released (as we were working on the review) V-Ray 1.1. This is the free Tuscany scene made available on-line by Holger Schoemann. I´ve rendered them both out with the settings that each came with. AR3 produced warmer textures but I found the V-Ray render to be sharper and more accurate. If you look carefully at the AR3 render in the top left hand corner there are some patches that appear to be blurry compared to the same part of the V-Ray render. Still the AR3 result is pretty good. The V-Ray render was almost an hour quicker at rendering. I think at the end of the day you would expect better renders from V-Ray since it costs more and likely has a lot more developers working on it than what AR3 does.


Release 11 Render time 2.18 - Click for a larger view	V-Ray 1.1 Render time 1.23- Click for a larger view

One handy thing now is the Auto Light option no longer needs disabling when rendering with GI.

Render Settings

I won´t go into a detailed explanation of every setting in the new Advance Render module but I will give you an overview of some of the newer options and what they affect.

You will find caustics under Effects in the global settings. You are now able to activate surface or volume caustics independently of each other not only in the render settings but in your material settings under the illumination heading as well. A third setting for caustics is in your light settings. At least one light is needed to take advantage of the caustics options.

Caustics Tab

Caustics Settings in Material Manager

When you activate the GI effect, under the "General" tab, you will choose your mode of rendering first. This is a very important step as it will determine the sampling and ray distribution. There are 6 modes from which to choose, all depending on your type of scene and lighting. You will need to learn a bit more about the different types so that you can make the correct choice. The six options are:

IR (Still Image) Slower than IR+QMC Still Image.

IR (Camera Animation) Best for fly-throughs and animations where the camera moves (slower than QMC).

IR + QMC (Still Image) Faster than IR Still Image

IR + QMC (Camera Animation) For fly-throughs and animations where the camera moves (faster than IR).

IR + QMC (Full Animation) For static objects and/or lighting that will be changing.

IR + QMC (Net Render).

Sky Sampler - A mode which will allow for sampling of a HDRI image on a sky object. It produces a very nicely detailed render.

GI - General tab settings

Under the Irradiance Cache tab, you will find a list of settings for even more in depth control. They are:

Stochastic Samples - The higher your density, the more samples you will need. They are interdependent.

Record Density - How detailed you need your image. More density equals longer render times.

Interpolation Method - The method of how the calculations are blended. Least squares is suitable most of the time.

Smoothing - The method of minutely blurring the samples to diminish noise.

Details Enhancement - When close up detail is necessary. It can add 50% to render times in some instances.

GI - Irradiance Cache tab settings

Behind the Oversampling option, you will find eight choices. If your scene includes lots of reflective materials, you will find that oversampling will speed up render times due to the fact that it forms extra rays that focus only on the illuminating materials. When choosing oversampling, make sure that you go into your reflective material and in the Sampling Mode under the Illumination option you choose Oversampling as your sampling mode. See image below for where to find this option.

Material Manager - Oversampling settings

Another option in your materials is GI Portal. This shows when you have Transparency selected. Let´s say you have a window in your scene and you´d like light to be projected from that window. By adding a transparent (to any degree) material and enabling GI portal in your illumination options you can create a much smoother and brighter casting from your sky through that window. Make sure that you don´t forget to choose an oversampling mode as well when you enable the GI portal.

Material Manager - GI Portal settings

You will find that one of the time savers in the new AR Module is the ability to save your Irradiance Cache to a file which can then be re-used. Even if you change other settings, this file will really save on render times by being already calculated and used again. Just load it as you would any file in your render settings.

GI Settings - Irradiance Cache and Irradiance Cache file tabs

Under the Details tab you will find options to choose a percentage for your Glass/Mirror optimization and select Refractive and Reflective Caustics. You need to remember to set these options in your material settings under Illumination as well, if you use them.

GI Settings - Details tab

Sky Shader Object

Another really nice addition to the GI rendering is the Physical Sky option for the Sky Shader object. Physical Sky is basically a true representation and accurate simulation of the sun and sky´s natural color and brightness. This is affected by the user´s input of location, time of day and month of the year. The Physical Sky interprets either the warm colors or the chroma color map depending on user choice and uses the exact spectral colors contained therein. You can also create an atmospheric perspective effect by using the controls under the Atmosphere tab.

A variety of controls are at your disposal including:

Custom Horizon - you can define a custom color gradient for the sky.
Max Altitude - user input will define where the gradient lies.
Color - defines the way the gradient is projected onto the sky hemisphere.

The following 3 images have the Physical Sky option enabled. The only difference is the date. Click on the image for a larger version.


August	October	November

As you can see in the images, different times of day, different months of the year and your internal settings can control the color, intensity and direction of light. The following 2 images show the difference between rendering with the Physical Sky option disabled and enabled. As you can see in the image on the middle with Physical Sky disabled the scene takes on the hue of the sky. With it enabled in the image on the right, the render is much more realistic. I have included a R10.5 / AR 2.5 render. The result is the same blue hue applied to the scene but with the inferior GI the image is patchy in places and no where near as good as the R11 / AR 3 renders. Click on the images for a larger version.


R10.5 / AR 2.5	Physical Sky Disabled	Physical Sky enabled

Conclusion

I think you will find that the new Advanced Render Module is an upgrade that´s been needed for a long time and MAXON came through for us. There is still a bit to do but the rendering improvements in Release 11 / Advanced Render 3 are a huge step forward.