I am using 3dmaxs 9 and I’ve got a problem when i am rendering with Mental Ray.
Doesn’t matter what material I use in any object but when i apply visibility to that object,
per example 1 to 0, (fade to nothing) the sequence is always rendered in the level of “1”
it means that the object disappears suddenly, I want the object to dissapear gradually,
but Mental Ray doesn’t do it. If i use the “Scanline Renderer” works perfect.
Where is the problem?
Thanks very much for your help!

The basic problem is, mental ray does not support Visibility.

Workaround:
Use your material as one in a Blend material. Have the other material with 0 opacity. Animate the Mix Amount.

Tim Wilbers [FA]

College of Arts and Sciences
Department of Visual Arts
University of Dayton
http://www.udayton.edu/
3ds Max: 7.5, 8, 9, 2008, 2009, 2010

doesnt mental ray have issues with blend and composite material ??

Digitaldruid 11 November 2007 01:01 AM

doesnt mental ray have issues with blend and composite material ??

Practically no more, or there are always a workaround.

Anyway the Tim’s suggestion is working without problem when using standard materials in the Blend material.
If two Arch & Design materials are used, one have to animate the Reflectivity (Highlights) to “0”. (This method gives actually, only a faked animated invisibility.)

Better result gives a “Cutout” map in a single Arch & Design material, animated from white to black.

I haven’t try this in Max 10, (still not installed) but it seems to me the problem with the unsupported animated visibility remains. Correct me if I’m wrong.

ivan

The Blend-Material with fade to nothing is wokring fine, but if you want to render an ambientOcclusion-pass, it´s still not working. This means, that the objects are invisible, but are anyway causing (ambientOcclusion-) “shadows” on other objects.

Does anybody have a soultion for this?

greeetings, d.

http://www.lightshape.net

3dclassen 14 November 2007 05:20 AM

The Blend-Material with fade to nothing is wokring fine, but if you want to render an ambientOcclusion-pass, it´s still not working. This means, that the objects are invisible, but are anyway causing (ambientOcclusion-) “shadows” on other objects.

Does anybody have a soultion for this?

greeetings, d.

I did not find a workaround, because animated “max distance” and shadow color” by AO, are not supported. Anyway this is Autodesk who must find the solution not we.

I don’t know why all this is so hard to be achieved, without the opportunity to animate the object visibility MR is just not a perfect tool.

At least in Max10 they killed the bug showing an object “invisible to camera”, when behind another object having a kind of transparent material. Not bad, but there is still a work to be done.  :)

ivan

This tread has stopped for a while but I have recently came across the same problem.

The workaround suggested above works well but what happens if you have a more complex set up.

What if the object that you want to fade away is made up of several objects, all with different materials.

1)Do you have to animate each of the materials’ blend values one by one?
2)and what if you want to fade several duplicates but at different times? Does this mean that every duplicate will have to have their own material because of their slightly different blend timings? ie anything that fades away will need to have its own material. It doesn’t sound like a good method to me.

Have I understood this correctly?

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

If the object that you want to fade away is made up of several objects, you will need to animate all them individually what ever render engine you are using, Scanline or MR.
If all this happens in different times it is even more complicated.

Anyway here is a solution when the objects are sub-objects; one of the materials of the Blend could be a Multi Sob-object material, the other one “invisible” material and the Amount animated from 0 to 100. (See Attachments.)

ivan

	Attachment

	Attachment
visibilitytest.mov

Looking at ya example, I think I did understand the technique but it is as I feared. This method will be time consuming if you have lots of identical (or even not identical) objects fading in and out at different times.

You mentioned this would be true whether using scanline or MR. I don’t think this is true because scanline supports visibility while MR doesn’t. This makes fading in things so much quicker (though there is issue regarding the fading in and out of shadows but that is another subject).

Example 1, to fade out an object with alot of materials in scanline, all you need to do is select the group and then animate the visibility instead of animating each material individually.

Example 2, to animate identical objects to fade in but 10 frames apart, all you need to do is animate the visibility again and then duplicate the object and shift the two keyframes along the timeline. Very easy and quick to do. To do this for MR will require multiple materials with different keyframes (and bearing in mind shifting the material keyframe is not a matter of shifting the keyframes in the timeline but actually manually re-assigning the keyframes again and again.

I hope I am wrong but is there a better way than this?

Regards

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

Okay, cheers for your advice guys. I will weigh up may options.

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

The Blend-Material with fade to nothing is wokring fine, but if you want to render an ambientOcclusion-pass, it´s still not working. This means, that the objects are invisible, but are anyway causing (ambientOcclusion-) “shadows” on other objects.

Does anybody have a soultion for this?

That’s another bug, the AO on A&D materials doesn’t respect the Cutout opacity.
To make a totally invisible null material for the other part of the Blend, start with a blank “mental ray” material, put Transmat in the Surface and Shadow slots. The result is a material that is nothing, it doesn’t render at all, no AO, no highlights no shadows, nothing.