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View Full Version : 3DS Max - One Light, Good Quality, Sans MR



stusic
2008-07-09, 05:19 PM
I don't know whether I'm getting lazy or just like simple things, but I've lately been using a single light in my scenes -- one skylight -- and use the Light Tracer instead of using mr. I get pretty good results and it cuts out a bunch of time lighting. What do you guys think of this method?

Cheers!

loydg
2008-07-10, 03:49 PM
Phil,

You won't get any arguement from me on easy set-ups. I also like to save out presets as often as possible so I don't have to go through the same process every time.

However, I have a couple thoughts on using the Skylight and Light Tracer. It does produce some nice "GI" but I've found render times to be unacceptable (too long) for my tastes, especially if using shadows and more than one bounce. AND, don't even get into trying to run a senqunce using it.

Although the Skylight/Light tracer method is really easy to set up, the Mental Ray Daylight System is also fairly easy to set up, more flexibility and acceptable render times. Just a few more check boxes and setting to get the best GI. Being a V-Ray user, I have a single light set-up that utilizes HDRI in the GI Environment override. Either way is pretty quick and should have better render times.

I'll see if I can work up some tests.

loydg
2008-07-10, 06:32 PM
So out of curiosity I thought I'd run a little test to see if I really know what I was talking about. Using the same base model, I set up a max file using Scanline Light Tracer, Mental Ray, and V-ray using their own lights (just one per scene) and various settings. I do have my gamma set for V-ray, so some of these came out a little darker than what I had intended. Below are the rendered results of the test. I'd post the settings images but those can be found in the attahced Max files.

Light Tracer:

This test only required placing the Skylight, turning on Light Tracer, and setting one bounce.

http://www.pbviz.com/forum/Uploads/Images/140f59f7-c8ac-46ba-b2bd-8297.png

Average render time: 00:01:23

Light Tracer Comments: The set up was really easy and only required eidting one setting (I added 1 bounce). All other settings are defaults.

Mental Ray:

This test required setting up the mrSky (and adjusting its angle), adding mr Physical Sky to the Environment, Setting Exposure controls to Logaristhmic, turning on Exterior daylight in Logarithmic settings, and enabling Final Gather.

http://www.pbviz.com/forum/Uploads/Images/3e223379-80ac-4116-b36f-47b3.png

Average Render Time: 00:00:06

This alternative requires a little more set up and has more variables. For a non-Mental Ray user, I was able to get in and figure it out fairly quick and would probably know exactly what to do if I was an avid MR user, so some of my setting could definitley use some tweaking. I don't like not being able to control the color of the Physical Sky other than moving the light. A lot of guess work and test renders involved.

V-Ray:

This test involved using a VRayLight and setting it to Dome (default settings), enabling GI Environment (default settings), enabling Indirect Illumination using only the Primary Bounce set to Irradiance map at medium.

http://www.pbviz.com/forum/Uploads/Images/e41ff939-f1ea-4306-8dce-55a8.png

Average render time: 00:00:35

I thought that V-ray might actually be a little faster than what it turned out to be. It has a similar look and feel to the Light Tracer test, but at half the render time. I also checked to see if using a V-ray material would affect the render time, but nothing noticable there.

As you can see, the results of each are pretty different. I've attached the test Max files below for those of you who would like to play. Since I'm not an expert on MR, I'd be curious to see some other optimizations that still produce a decent rendering.

stusic
2008-07-25, 04:37 AM
Why does mr make the scene so blue? That's one of the biggest issues with mr that I'm having, that it messes with the colors of my scene...

loydg
2008-07-25, 12:54 PM
I really don't know. One of the guys in our office was able to get VRay to mimic the MR and get the "blue" effect. I struggled with it too. Perhaps Steve can tell us why?

Steve_Bennett
2008-07-26, 06:40 PM
Well, its kinda easy to describe. In the past some might have used one omni light to generate diffuse light and a second omni for ambient light only.

mr Sun produces your direct light (or diffuse).
mr Sky produces indirect light (or ambient).

In the sample scene you posted, there was only the mr Sky and no mr Sun.

If you go to the Create panel > Systems > Daylight, it will create both objects at once which is the recommended thing to do. In the first image I posted (cyl arch design.png) I swapped the standard material for an arch & design mr material to see if there was a change (none really noticable).

The second image I posted (cyl arch design daylight system.png) I replaced the mr sky object with a Daylight system set to manual and eyeballed its position to match that of the mr Sky that was originally in there. Once that was rendered the output more closely matched that of the other images.

btw, what killer system were you using to render those images???

loydg
2008-07-28, 12:49 PM
Good to know, Steve! That's why I love forums like this.



btw, what killer system were you using to render those images???

I guess I should have mentioned that with the render times:

Dell Precision T5400
8 Intel Xeon (E5430) 2.66GHz CPU
8.0 GB RAM
Nvidia Quadro FX 3700
240 GB HD
Windows XP 64

Pretty good and stable systems as long as we can keep IT off of them...;)

Steve_Bennett
2008-07-30, 05:03 PM
Good to know, Steve! That's why I love forums like this.



I guess I should have mentioned that with the render times:

Dell Precision T5400
8 Intel Xeon (E5430) 2.66GHz CPU
8.0 GB RAM
Nvidia Quadro FX 3700
240 GB HD
Windows XP 64

Pretty good and stable systems as long as we can keep IT off of them...;)Drools...

EIGHT cpu's??? Good lordy that explains the render times you posted. :beer:

Well, I can dream I suppose!