I am creating a mushroom cloud, following the tutorial here: http://www.the123d.com/tutorial/3dsmax3/explode02.shtml However, I have run into a problem. Instead of the blend maps blending the 3 explosion materials correctly, the grey material covers the entire object and there are tiny traces of the other colors where the dark red color is on it. I have checked my UVW mapping and it is mapped correctly (the gradients appear correct when I activate them in the viewport, but they render as pitch black) and each map is set to a different id. Any ideas how to fix this?

3ds Max Design 2012/Maya 2012
Intel Core i7 3.07 GHz, 8gb RAM
AMD Radeon HD 6950
Windows 7 Home Premium SP1 x64

I’m not sure what is going on with your scene, but I would suspect it may be a units related issue.  Can you zip and upload your scene here so we can see it?

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

sure, here it is.

3ds Max Design 2012/Maya 2012
Intel Core i7 3.07 GHz, 8gb RAM
AMD Radeon HD 6950
Windows 7 Home Premium SP1 x64

	Attachment
mushroom_cloud.zip

Your Gradient Ramp using the Radial type is currently set to Map Channel 2, and should be channel 1.  But for some reason, the gradients don’t want to render properly with the Displacement Approx. modifier applied.  If you turn it off, the cloud renders correctly. 

It also renders correct if you disable the Displacement in the materials used in the Blend.  I’m not sure why that would mess with things, to be honest.

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

youre right. I’ll have to keep messing around with it. I’ve never actually used the displacement approx. modifier, so I dont really understand it. It definitely has something to do with displacement approx and cellular dispalcement, is there a way to replicate the effects of cellular displacement with a modifier or something? you know, actually change the mesh to be like that?

3ds Max Design 2012/Maya 2012
Intel Core i7 3.07 GHz, 8gb RAM
AMD Radeon HD 6950
Windows 7 Home Premium SP1 x64

There is a Displace modifier that you could plug your Cellular map into.

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

yeah I tried that. It didnt quite work. It did create a similar effect, but there were some problems. The displacement map in the texture doesnt appear to rely on the amount of polygons in the object, but the displace modifier does. So areas with less polygons, such as the “stem” of the mushroom cloud, weren’t so much displaced with a cellular map as scaled upwards non-uniformly. That created some weird proportional errors, and a lack of cloud-like detail.

EDIT: I tried applying a turbosmooth with 2 iterations to increase the polygon count before using the displace modifier, but it appears that detail level alone isn’t causing the strange proportions. I think it’s because the uvw map isnt the exact shape of the cloud.

3ds Max Design 2012/Maya 2012
Intel Core i7 3.07 GHz, 8gb RAM
AMD Radeon HD 6950
Windows 7 Home Premium SP1 x64