View Full Version : Mental Ray vs C4D Advaced Renderer

05 May 2010, 12:56 PM
I'm a Maya user, but I am looking into Cinema 4D. I'm wondering if anyone who has used Cinema Advanced Renderer and Maya with Mental Ray could give me a little insight.

Seems that C4D's AR is way faster. The renders below were done with the same ibl. Maya MR only has Final Gather enabled with the settings as shown and antialiasing is default production quality. The C4D render, below, has global illumination set up, antialiasing best. The Cinema 4D render looks way cleaner, compared with the Maya render, which is splotchy. The C4D render also took around ten seconds as the MR render took one minute and 20 seconds.

What is going on? Any insight as to what I am doing wrong in Mental Ray? Or is AR better at this kind of thing?

C4D 11.5
Maya 2009


05 May 2010, 01:24 PM
The big thing that puzzels me is the quality you are getting from MR with those FG settings. In my experience, those settings are much higher than anything I have needed for production quality output.

I was wondering if the problem may be in your IBL setup. Perhaps, if you have the Emit Light option enabled on the mentalrayIblShape, the quality settings in there could be where the splotchyness is coming from...and the extra render time. But this is just a thought.

Looking forward to seeing how this one progresses.

05 May 2010, 01:30 PM
I think the Advaced Renderer in the next Cinema 4D release kicks mental ray down in speed and easy to setup

05 May 2010, 03:20 PM

This is by no means a "scientific" test. Just feeling that AR is faster and cleaner.

I don't doubt that Mental Ray can as well or better, but it's not clear to me how to set it up. I set the settings higher in Mental Ray to get a tighter shadow on the cube. AR seems to render it a bit tighter and cleaner with the default setup.

It's actually pretty much the same setup in both scenes. Just an hdr attached to the luminosity/incandescence of a material. There are no "lights" in either scene, just the hdr ibl.

05 May 2010, 03:20 PM
Linear Workflor is the key

05 May 2010, 03:54 PM
| Linear Workflor is the key

Yes, thanks. These are both gamma corrected.

05 May 2010, 04:07 PM
In MR, are you using the optimized IBL setup (it does not sound like that to me when you say you are using a normal material)? (In the render options on indirect lighting click create, and attach the texture there.) I recommend you lower your FG settings to the defaults.

05 May 2010, 04:24 PM
|In MR, are you using the optimized IBL setup (it does not sound like that to me when you say
|you are using a normal material)?

Yeah, but I'm trying to create a model of a light. So I'm using an hdr of an umbrella reflector connected to a small piece of geometry, both in Maya and C4D.

Should I be using a particular type of material for this in MR?

05 May 2010, 05:02 PM
| Linear Workflor is the key

Yes, thanks. These are both gamma corrected.

Nope ;)
But I don't think you're using a lens shader in mentalray right now.
If you are, probably your settings are too low.

05 May 2010, 05:20 PM
for soft lighting in mental ray try using mia_portal_light. use regular maya area lights, open up the mental ray tab and check "use light shape," bring your high shadow samples up a bit, then connect mia_portal_light as the light shader for the area light. i usually connect an mib_blackbody in the custom environment slot for color temperature. for the reflection of the light, use those umbrella things you made but tell the geometry to not cast shadows and only be visible in reflections.

you may also want to remove the cards from final gather by adding a boolean attribute to the card's shape node called miFinalGatherHide and setting it to 1. that way you get all the nice FG from your portal lights and nice custom reflections from your cards.

also check out mia_light_surface in the mental ray architectural guide.

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