Tuesday, November 26, 2013

Revit rendering vs. Autodesk cloud rendering - Fight!

Recently I had the pleasure of designing a few options for a potential remodel of our lobby here at HQ. During this time I also trialed Autodesk 360's rendering service and I must say, I am impressed. What I liked most about it was the speed with which it rendered. The quality of the images was fair/good and the way it handled material textures was good, in fact in some cases better than Revit. But then the cloud handled some things a little oddly.
Looming deadlines are the modus operendi for Architects. Unfortunately for us, renderings usually take time and unless you have workstations set aside for rendering, you've got to juggle your time in Revit and your time rendering such that you can accomplish what you need in the nick of time. Well at least you used to have to juggle your time. With Autodesk's 360 cloud rendering, juggling time has become less of an issue. The cloud is FAST. And it's easy. Take the two draft images below for example. Both were set to roughly equivalent quality and size settings, though the model was at a different level of completeness in each which should explain the subtle differences. Revit took 1 day, 9 hours and 24 minutes to render. The Autodesk cloud took roughly 10 minutes.

Draft image rendered in Cloud (Final, Large, Advanced setting)
Draft image rendered in Revit (Best setting)
There are some noticeable differences though. It seems as though the cloud uses a different rendering engine. In fact if you check the Help, you'll find this statement:
"The rendering service relies on a new, highly optimized rendering engine. Minor differences in the appearance of materials should be expected."
In general the Revit rendering has a softer look to it which I like.


Note that some of the materials are not showing up in the cloud rendered version for the bar, and the chrome of the coffee table. These use stock, out-of-the box materials (Cherry and Chrome) so I sent off a note to the nice support folks about it. Apparently there's an issue using the "Tint" feature in the Revit material editor, though this was not used in these materials. They're looking at the file at the time of this writing and I'll try and update this post if I get a response/solution. I changed the materials for these elements to Wood - Cherry and Metal - Chrome and it rendered fine. 
The wall paint is also very different in appearance in the two different renderings. Some of this has to do with the exposure settings but the mottling of the material is typical Revit rendering effect. If you adjust your rendering settings in the Custom options, you can eliminate the mottling but I find it comes with a time cost.
The textured wall behind the receptionist turned out to be incorrectly rendered in Revit but correctly rendered in the cloud. As far as I can tell the texture and the bump are not aligning correctly even though they were locked and use the same image:

Rendered in Cloud

Rendered in Revit
Not so good


The lighting in the above draft has not been adjusted in terms of color. To make the fixtures glow, I created a new material called "light glow" and set the Self Illumination to create the fixture glow:

I later adjusted the color to match that of the fixtures photometrics. 

The lighting in both looks fairly good but in both the Cloud and Revit I had to adjust the exposure and white point to get the right brightness and tone. 
The odd thing about the lighting is that in the cloud rendered image, there's a black plane showing up in the fixture, perpendicular to the direction of the luminance, that is not in the family and isn't rendered by Revit. I ended up switching out the fixture for a different one as I couldn't find a way to eliminate it. 

Rendered in Revit
Looks correct
Rendered in Cloud
Ummm, wtf?

At the end of the day, I ended up finalizing the design and rendering 6 or so images via the cloud, blowing through the 25 free "cloud credits" and generating some good images for the presentation. I recommend you use the free "standard" setting until you are completely satisfied with the output materials, textures, lighting and so forth, before you spend your credits on rendering a "final"  Large image.  The dialog will let you know how many credits are required and this website has a breakdown of cost and the different settings. All in all the convenience is well worth the cost. You get 100 Cloud credits allocated annually for each software license on Subscription. According to the Revit Kid, Autodesk Cloud credits cost a buck each.

Rendered in Cloud

Rendered in Cloud

Rendered in Cloud


Anonymous said...

Seriously its a big difference.We spend time on selecting the right material according to how it shows up when we render and sending it to the Cloud every time we want to check a material becomes inefficient.
Really, Autodesk should have looked at this before offering the service.

Anonymous said...

This is mind blowing. I have been using revit for 4yrs, wit some excellent skill in modelling, yet the graphical output looks dull for my liking. Please can u talk me tru on the cloud rendering, i mean how do u and where u get cloud rendering settings

David Ajiferuke said...

This is mind blowing. I have been using revit for 4yrs, wit some excellent skill in modelling, yet the graphical output looks dull for my liking. Please can u talk me tru on the cloud rendering, i mean how do u and where u get cloud rendering settings

Deepthought said...

When rendering inside Revit - try adjusting the highlights up, midtones down and shadows down - you'll be amazed how much better this makes renders look.

Anonymous said...

look at octane