CGTalk - No reflections in Mia_architectural_x except for physical

View Full Version : No reflections in Mia_architectural_x except for physical_sky

Jamnique

01-05-2008, 01:04 AM

This is another annoying problem which seems to be a bug of some sort. I've been fiddling with the famous class scene introduced in the great "Vray like rendering in Mental Ray" thread, and came to an impenetrable wall.

The thing is that all my materials are based on mia_architectural_x and neither of them shows any reflections other than coming from physical sky or IBL. I spent a couple of hours trying to find out what could be causing this, with no success. It may sound crazy but after trying other materials it turned out they don't reflect much either.

I tried to do the same thing in XSI and MAx. I used exactly the same material settings in all the three programmes (same lighting as well) and guess what? It works like a charm except for Maya.

I guess it's either a mental ray for Maya bug or i'm missing something, perhaps some hidden-global-reflection switch? I'm sure i used enough reflection rays, in fact i've tried using massive amounts, with no success.

If someone give me some clue i would be delighted...
I'm using Maya 2008.

MasterZap

01-05-2008, 07:16 PM

Are you sure about the "no reflections" thing? Never ever saw that.

If you turn up the "brdf_0_degree_reflections", is there any change? Since it defaults to 0.2, most objects are only 20% reflective for most angles, which may make most objects not really turn out to be "visibly" reflecting, but the sun/sky, which is superbright, is more clearly visible in those 20% reflections....

/Z

Jamnique

01-05-2008, 08:44 PM

Wow! The mental god himself :D
Thanks for all the awesomeness in new Mental Ray 3.6 :D

Unfortunately tuning the bdrf curve or running reflections in fresnel mode with high IOR, as you suggested in your blog entry about rendering metal, didn't help in my case. (Also, i checked the same settings in max and XSI and they did work there).

My system's just died on me so i can't post a render right now (no maya onboard anymore), but basically, purely reflective surfaces render black if there's no area light / physical sky to reflect. They do not reflect other objects. I have a fully lit classroom with fg, that is apropriately bright, with the exception of highly reflective things that only show reflections of area lights in the windows, turning a blind eye to the rest of the classroom.

I'm using mia_exposure_photographic, but i've aslo tried mia_exposure_simple.

Jamnique

01-05-2008, 10:52 PM

I found this test image among the ruins of my disk, I hope you can see clearly what's going on. It has tons of reflection rays in it as far as I remember. Beware though, it's a damn ugly render :P

http://img150.imageshack.us/img150/9320/fg100d01s50ao506min24smv7.th.jpg (http://img150.imageshack.us/my.php?image=fg100d01s50ao506min24smv7.jpg)

epq

01-05-2008, 11:38 PM

This isn't by any chans an imported OBJ from the original max scene ?
If so maya sets the visible in relection / refraction to off for all object.

Have a look at some random objects render stats :thumbsup:

Jamnique

01-06-2008, 12:27 AM

I can't believe it's that simple! I can't do a test render because the scene is corrupt after recovery, but i can see now where reflections are switched off.

Thank you sooo much! :D And sorry so much for wasting your precious time... I simply checked the mental ray settings for reflections and obviously missed maya's own Reflection/Refraction switch. And i was so sure i tripple-checked everything... How incredibly noob of me.

Sorry and thanks once again...

CGTalk Moderation

01-06-2008, 12:27 AM

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.