Hello

I am looking for a 3ds max 9 plugin of chroma key which could take out blue/green color ffrom a video/image for compositing.

You don’t do this in max. You do it in a compositing app (Nuke, Fusion, Shake, After Effects, Combustion etc etc). Infact, you shouldn’t render anything right onto a backplate. Rather render out with passes, or just an alpha, and put it on top of your footage in a compositing app. If you don’t know how - Now is the time to learn ;)

Tobey
VFX Artist/Compositor

http://www.elitevfx.com

Someone asked a similar kind of question in another forum. You can do basic form of this in 3ds max using gradient ramp mapped to a color and then using the resulting map as a mask for the footage or image. I copied over the response I made:

For example, if you use a Gradient Ramp map in the opacity slot of the material that is playing the footage, you can set the Gradient Type of the map to Mapping and the Source Map to your footage. Then by using only shades of white/black for the flags in the Gradient Bar, you can map by color range in the footage which parts of the footage should be solid black or white, or some variation thereof, effectively creating a mask or alpha channel.

See here is an example image:

Made a little jing file:

Plane on the left containes the unmasked image/footage.
Plane in the middle shows the resulting alpha mask from the procedure of keying out the green color
Plane on the right shows the result when the footage and alpha mask or put into one material in the proper map slots.

Video of it

You don’t do this in max. You do it in a compositing app (Nuke, Fusion, Shake, After Effects, Combustion etc etc). Infact, you shouldn’t render anything right onto a backplate. Rather render out with passes, or just an alpha, and put it on top of your footage in a compositing app. If you don’t know how - Now is the time to learn ;)

I agree. That’s what Compositors are for, it’s not what Max is for. Max is not a compositor, but is great when used in conjunction with a compositor.
If you need to do this kind of work, then I would seriously consider getting a compositing program and use it along with Max.

You can do basic form of this in 3ds max using gradient ramp mapped to a color and then using the resulting map as a mask for the footage or image.

That’s a nice idea, but what you actually have there is a Luma Keyer, not a Chroma Keyer. The chroma of the image doesn’t figure in the resulting key, the mapped gradient is driven purely by the luma values of the image.
It may work on nice perfectly flat painted images, but real chroma key footage is rarely like that. Even a well lit green screen will vary in luma with light and shadow, and the subject will likely vary in luma values a lot, above, below and more importantly equal to the luma of the screen.
It won’t work with chroma unless you pull apart the individual colour channels of the image, process them and recombine them in a correct way.
You would have to do a luma key on the Green channel so a certain level of green value keys. But, white yellow and cyan pixels have a high green value, so you will have to also luma key the red and blue channels and use them to mask the mask to cut off the high G pixels where the R & B levels exceed limits. That’s too much hassle for something that won’t work that well in the end, you need a compositor.