haneet khanna

Hi everyone



Ok i will start with my question straight away.



I want to know that how to save an alpha channel inside an image.Suppose i have a tree image and i made an alpha channel that is black and white image out of it and added a new channel from the channels pallette in PS.It automatically names it alpha1. I put this black and white thing in that channel. IS this method right and what formats support alpha channels i mean tiffs tga jpgs etc....



Secondly i have an image of tree in tiff format with a stored alpha channel in it. But when i use it on a plane inside max it comes with the background. how can i tell max to use the stored alpha channel..I don't know but i am trying to use composite map and i am not able to find the solution for storing alpha channels and using them in max..



PLease help..



Thanks

HAneet

Jeff Mottle

Hi Haneet,

Alpha channels can only be saved in some file types, JPG is not one of them however. Most people save images that contain alpha channels in either TIF or TGA.

To use the alpha channel in MAX you need to edit the bitmap parameters in the material. You can specify the alpha source in the "Alpha Source" section.

Another quick note is that the cutout will not always show up properly with some OpenGL drivers. Software mode will always work. (Customize ->Viewports->Choose Driver)

__________________
Jeff Mottle
CGarchitect.com

ccouto

other note.
sometimes you can have problems with the GI in alpha chanels, like have a shadows in transparent surfaces.
with brazil and other render engines...

haneet khanna

Thanks jeff...
I tried to follow your steps...i selected the alpha source as image alpha but it makes the the transparent parts greyish but not completely transparent and i have checked that the in the alpha channel of the image the colors are true black and white colors.Then why not completely transparent .Why greyish?????

Am i wrong anywhere..Please help

Haneet

abicalho

You most likely have some shininess in your object. A transparent object with shininess will show the transparent part's specularity. You either have to set the shininess and shininess strength = 0, or you have to add to clone this map into the shininess map, in order to avoid the "transparent" part to show up.

An easier option is to use the alpha map in the Cutout map of an Architectural material.

Hope it helps,

__________________
Alex Bicalho
http://www.origamy.com.br/blog

haneet khanna

Hi All

Please tell me how to use Composite map in max(not composite material)
SHinniness thing is also not working..It still shows it gray....

ccouto

hi again

i think that you need to mix the maps in the output parameters.
but in this case, to use only a alpha map and some difuse or specular map, a mask map is enought.
i wish i help you.