3D Cloud Models is a collection of 15 curved-billboard meshes with photoreal cloud textures. They're very quick to render and you can even tweak the ambient and sun color right inside the material!

Features:

15 low polygon models: Duplicate, move, rotate, and scale the clouds in your scene to create epic skies and artistic direction.
Adjust the sun and ambient color by adjusting the material. Or, setup your own in your 3d app of choice by using the RGB channel of each texture as a blend map.

OBJ, FBX, and MAX files included. Max file is for Max 2011+.

3D Studio Max Setup

Compatible with 3DSMax 2011+.

It's all setup for you. Just load the 3D Cloud Models.Max file. Each cloud is on a master multi-subobject material. Cloud 1 is on material 1, Cloud 2 is on material 2, and so on. The opacity is controlled by the alpha channel of the associated texture. The diffuse Mix material allows you to control over 2 colors; the sun (color #2) and ambient (color #1). Each material is self-illuminated.

Maya, Blender, Etc.

You can import either FBX files or the OBj file which includes all the clouds. The material setup is not included, so you will have to author it yourself.

3DCloudModel_1 uses 3DCloudModel_1.tga, 3DCloudModel_2 uses 3DCloudModel_2.tga, and so on. The alpha channel of each texture is for opacity/transparency. To setup the sun and ambient control, you will have to setup a blend colors or mix between two colors (sun and ambient). Use the associated texture as the blend map.

Quantum Theory