Some questions have come up about methods of rendering a scene that goes from night to day (or day to night). I'd approach it as though I was using a real camera by animating the exposure settings.

Here's a "proof of concept" quickie animation showing the results:
http://jeffpatton.net/Blog-images/Exposure_test.mov
(It may be best to right-click, save as the link instead of directly viewing it)

In that particular 3ds Max9 scene I animated the brightness value of the logarithmic expsosure...rather roughly I have to admit, but this was just a quick test. WIth more time to tune the brightness animation you'll be able to achieve a smoother transition.

I also adjusted the mr Physical Sky used in the environment map. First, turn off the "Inherit from mr Sky" option to manually adjust the sky map for the background without messing up the mrSky that is providing light to the scene. Then I simply animated the multiplier from 0.0 to create a black sky for night, then 1.0 for the daylight portion of the animation.

For reference, here's the 3ds Max9 scene:
http://jeffpatton.net/Blog-images/Exposure_test.zip

This process is easier in 3ds Max 2008 with the photographic exposure control. For that, you'd simply animate the shutter setting like a real camera.

Tried the mr Sky Portal yet? Good stuff eh? Well, don't forget that you can use the mr Sky Portal lights for more than just skylight portals. They work great for visible area lights as well. In this tip I'll show you how you can add kelvin temperature control to the sky portal lights and use them in your scenes as area lights.

In the first step you'll need to modify the base.mi file to remove the hidden tags from the two shaders in the light utility section. So, open the base.mi file in your favorite text editor and scroll down towards the bottom to the "Light utils" section. Once there you'll place a pound sign in front of the "hidden" tags on both the mib_cie_d and the mib_blackbody shaders.

Next, you'll need to modify the apply type on both as well. These shaders are actually light shaders and can currently only be applied to light sources...HOWEVER, you can simply add the apply type "texture" and you'll be able to use them as a texture map to give the portal lights kelvin capabilities.

Here's a visual of my base.mi file highlighting the changes I outlined above:

(be sure to add the comma after "apply light")

Once the base.mi modifications are complete, add a mr Skylight Portal to your scene. In the advanced parameters rollout enable "Visible to Renderer" and select custom for the color source. Click the button next to Custom that's currently labeled "None" and assign either the mib_cie_d or mib_blackbody shader. Of course you'll need to drag an instanced copy of that shader to the material editor in order to modify the color/temperature and brightness.

And here's an example render using two portal lights with cie_d shaders applied (click to enlarge).


I did not use any indirect illumination in these examples because I wanted to illustrate the portal lights diffuse illumination of the scene. But remember the mr Sky Portal obviously works great with FG, but they also will emit photons if you wish to use them with GI.

Ever wished that you could take the great rounded corner option from the A&D material and apply it to other materials like the CarPaint material or Fast SSS skin material? Well, good news...you can.

First thing you have to do is open your "architectural_max.mi" file in your favorite text editor. Once open, scroll down to the "gui_mia_roundcorners" section and simply add a pound sign (#) in front of the "hidden" command. Here's a visual reference:



That's it really...simple eh? Well, with that task completed you'll now be able to access the round corners bump map inside 3dsmax (and outside the A&D material). Here's a few examples:

Round Corners applied to the Fast SSS Skin material (click to enlarge)


Round Corners applied to the Car Paint material (click to enlarge)

NOTE: Since the Car Paint material does not technically have a bump map I found that I could make it work by using a blend map. Just place your carpaint material in the Material 1 swatch, and the round corners bump map as the mask (and ignore the material 2 swatch). Presto-blammo, you now have rounded corners on your carpaint material.

More handy plugins:
If you haven't tried CrazyBump yet...you're missing out. It can easily make bump/displacement/normal maps for your favorite texture map. If you're like me, you have several nice diffuse maps, but no matching bump/displacement map...now I can quickly make one with CrazyBump!

Website: http://crazybump.com/
Example test renders with displacement maps I've made using CrazyBump:

CrazyBump example 01 (click to enlarge)


CrazyBump example 02 (click to enlarge)


CrazyBump example 02 (click to enlarge)


Also, there's a new Ivy generator plugin that works directly inside 3dsmax here:
http://guruware.at/main/index.html

GW::Ivy (click to enlarge)


And finally in this update I'd like to announce that I'm now offering on-site mental ray training through Virtual Partners: http://www.virtualpartners.com/