IBL in 3ds max 2011

[Jenni722]

Normally with 3ds Max you need to add a light (a turned-off light) to disable the default lights that Max inserts into your un-lit rendering. Without adding this disabled light the rendering is lit, but it is also not looking like anything but default lighting as far as I can tell.

[bart]

Yeah, I set the light intensity to 0.0 or some small number if I'm testing direct light vs. indirect, or in this case IBL, which is a conversion of environment to a special direct light.

[bart]

And I'm not able to get the IBL working yet in 2011, either. Though, it is turning off FG from the environment as it is supposed to, while keeping FG from objects.

It is as if max's special environment handling is somehow getting in the way ...

[bzq]

this is my 2011 scene (32 bits) that i test IBL with my simple script to enable IBL mode. you can use this script work with ctrlghost to enable IBL but i don't know parameters in ctrlghost such as pass mode (shadow) working or not. but with my script only shadow mode working,
environment shader will process even you choose FG or not, but like i said when i add some light (i know max has default light) it render geometry black. i turn light off, it still black. remove light it come back again.

[Wobi]

Now, it seems to work, even with a bitmap as enviroment. But as soon as I create a light source, even if it's set to OFF or zero intensity, IBL renders black again. So if there is NO light in the scene -> IBL works.

EDIT: Doesn't work with Arch&Design materials but with Standard materials...

[bart]

Yes. I got it to work without the light as well.

Something very tricky. If I changed an existing material to an Arch&Design, it no longer worked. But if I created a new A&D and then dragged it to an object, ibl worked.

[bzq]

some one confirm it don't work in max 2011. but i think autodesk disable IBL if already have some light in scene and when in IBL mode it disable all other lights in scene.

since Maxscript say IBL, IP and Progressive rendering in Max 2011 for Experience. i think some one in CGTalk is right. we will find another way to do IBL in Max 2011

[steve]

Hi,
I suspect that native IBL has some trouble in 3ds Max because of the traditional light list handling on a per-shader level.

All shaders which are using mental ray's 'instance light lists' should pick up the IBL automatically without knowing, but shaders which look at the shader 'light lists' parameter will not unless the 'light mode' is set to 4. To my knowledge, in 3ds Max light contribution is controlled via shader parameters with the 'mode' parameter set to 0 for 'use these lights only', you 3ds Max gurus will find out. In this case, there is one exception where IBL may be used automatically: when 'mode' is 0 and the 'light list' parameter is empty. I feel this could explain the strange behavior reported in some posts.

Given that all of the above is true, then having a way to manipulate the 'light mode' parameters on shaders would help to get IBL working correctly. Another option is imaginable if light names could be passed to shaders explicitly, since the IBL light has a fixed name.

[strangerman]

Ok, i think i found a clunky way to make A&D material to work with IBL. (At this point i recommend to backup the files before save any change) Just unhide the mrArchmaterial from architectural_max.mi file and it will unhide the map gui for arch&design shader. It has a spinner to change the mode. Just plug the "map" into a source slot of a mental ray material and set the "mode" spinner to 2. Enable IBL and hit render. It should work even with lights in the scene, but not using them.
The bad news is that it only accepts values between 0 and 2, which is not bad, but the optimal value is 4 so we can use IBL + lights. To do so just open the architectural.mi file (NOT architectural_max.mi) and search for the "Architectural" shader declaration both 14 and 17 versions. Look for the value integer "mode" and leave the line like this:

integer "mode" default 4, #:min 0 max 4

save and open max. Repeat the A&D map+Mental ray material and set the diffuse weight to 1, cutout_opacity to 1 and mode to 4. Put a light into the scene and some hdri in the environment and press render. Voilà.
Doing this, all the shaders using intances of the A&D shader will work (not sure of this but it seem so in my tests)
Hope this helps.

jorge

PS Thanks for the ideas Steve!!
PS2 IBL settings from Crtl.Ghost doesn't work at all, just the script. Thanks bzq.