For this one I needed a scenery that looked like from a children's drawing so I drew all this little houses and storefronts and even street lamps were just simple planes with alpha chanel. There for I couldn't make my street banners look like a real cloth since that would ruin the whole concept
I will use this Jazz Session banner as an example
It is in fact a plane stretched between two poles
With an animated sequence asigned to it to give it a waving look
But first things first, lets see how we can make our banner in Photoshop. I used my Wacom to draw it's basic shape on white backround and than added text and ropes.Select all the white areas around it and
reverse your selection (shift+ctrl+i)Switch to Channels and click on -Save selection as channel - and you have your image with alpha channel
Now let's make an animated loop out of this. We will have to jump quickly into After Effects. Make a new composition and import your banner from Photoshop that you saved as targa (.tga). Your default alpha import option should be: Straight - Unmated leave it like that and click OK. Make your composition 10 sec long (250 fr) - Composition - Composition settings - Duration, also go to - Composition-Composition settings and change the size of your composition to match your image size ( displayed at the upper right corner of your composition window).
Note that it could happen that it still is not the same size regardless that it is the same number of pixels. This is because you may be using different Pixel Aspect Ratio. Then you'll have to right-click on your image and choose: Interpret footage - Main - and from - Other Options, pull down menu choose - Square Pixels or whatever other - Pixel Aspect Ratio you are working with and click OK
And let's add a flag effect to it
Go to Effect - Distort - Ripple and add it to your composition. A control window like this will pop up. You'll see the center of the ripple in the center of your composition; move it up all the way to the top. Make your Radius big enough to get ripples across the banner but not to affect the "ropes". Boost your Wave Width to 90.0. Now when you move the slider you should see your banner "waving in the wind'.
I encourage you to play with settings and try different effects that will suite your needs better.
Finally export this as a targa (.tga) sequence to a new folder in your projects Source images.
Back to Maya
Let's make our material first. Get a new Blin and for it's Color assign File node. Under File Attributes change the filter type to Mipmap and check Use Frame Extension box. Under Image Name browse to the first frame of your image sequence and double click. Assign this material to a simple plane that you made to match the size of the imag
Note that your Transparency will automatically be connected to this image's alpha channel. This will make your material translucent and just the banner will be visible on the plane but there will be no animation yet.
Controlling your animation
To make your frame sequence work and to have full control over when it starts and stops we'll have to add a Frame Extension node. Just move the slider to a frame where you want your sequence to start and right click on frame extension in the Attribute Editor - Set Key. Move the slider again for the number of frames of your sequence and again Attribute Editor - Set Key
Now go to Frame Extension Attribute
Window and change both Anim Curve Attributes to Cycle and for the second Key Frame Value enter the number of frames from your banner sequence.
Your sequence will now play between the key frames you specified, and you'll have a great impression of animated banner with just a simple plane in the scene
Rendering
However if you render now your plane will not be translucent all the way around the banner, especially if you have a direct light shining on it. There are two ways of dealing with this that I can suggest
First is to turn off Emit Specular from Light Attributes or Set Eccentricity of the material to 0 (which I personally prefer).