Making an old-school forest with planes, diffuse channel and opacity channel. Added is the problem.

In the standard material under the mental ray rollout. Ive added the mist, instanced from camera shaders.
When multiple planes interact they create an outline of the plane barely visible. (but visible)

Before i got finished writing this question, ive already found the solution. So i will post it so people with same problem can pick it up.

Change from your standard material to arch and design and use “CUTOUT” instead of opacity. And tweak the map to your wishes from there. Works like a charm right out of the “box”.  :)

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You’ve got it!  The Arch & Design materials work a little differently than the old Standard ones.  The Standard material let you make an object see-through or invisible just by adjusting the Opacity value.  The A&D materials have a Transparency value instead, and it makes it more like glass or something, where you have a refraction to it when it isn’t 0% transparent.

But the Cutout slot is where you go if you want to make part of something truly invisible instead of just transparent.

3DS Max Design 2011 64-bit - Advantage Pack
Dell Precision T5500, Dual Six Core Xeon X5650 @ 2.67GHz, nVidia Quadro 5000, 24 GB RAM, Win 7 Enterprise 64-bit
Minneapolis, MN, USA

Would this work with Facing particles and a z-depth element then? When i tried it before i would get the full square Facing Plane in my Z-depth instead of my round bubble material using opacity…

Q

Intel i7 920 with 6 gig Ram. 64 bit Win7. Max 2009 and Max 2011
Small 5 machine render farm of mixed machines.
More coffee please!  :-)

I don’t think the z-depth channel repects any material-based masking.  So even if you have a map in a Cutout slot, z-depth will still return the actual geometry faces.

3DS Max Design 2011 64-bit - Advantage Pack
Dell Precision T5500, Dual Six Core Xeon X5650 @ 2.67GHz, nVidia Quadro 5000, 24 GB RAM, Win 7 Enterprise 64-bit
Minneapolis, MN, USA