using a render as a 2D background object ?

fc633809

I want to use a building I use in one scene (farmhouse) as a distant background object in another scene (riders in landscape) I see some landscape generators use 2d images on a translucent background in that way.
So I made a render of the building without the environement (the checkered grey background) and tried to stick the image on a plane. Both .jpg and .png formats give me the image on a black background and I have figured out how to make the plane translucent  but then my entire image is invisible too.

Can someone help me with the right surface settings or doesnt it work that way ?

fixmypcmike

You need a transparency map, white (100% opacity) in the shape of the building, black (0% opacity) for the rest.

WendyLuvsCatz

to make a cutout opacity map in Gimp

have white as your background colour and black as your foreground

import the image

select by colour the checkered png alpha background and fill with foreground colour black, invert selection fill with background colour white.

(that sounds confusing because the paper/canvas is usually white and your paint/pen black and the opacity map is actually the opposite)

fc633809

Reactions are contradictory : white image on black background or black  image on white ?

Chohole

White for the areas you wish to show, black for the areas you don't wish to show.  This is on the trans map,  which should be in grey scale.

 

WendyLuvsCatz

fc633809 said:

Reactions are contradictory : white image on black background or black  image on white ?

I was just using the default that opens in Gimp which is black pen on a white background as the starting point

you could indeed swap it but it's an extra click you don't need 

explaining it to someone else just sounds bassackwards

fc633809

This is contracdictory. info Black on white background or whiteon black ?

Chohole

I repeat   your trans map should have white for the area that you wish to be visible in the render   and black in the area  that you don't want to be visible

 

Richard Haseltine

fc633809 said:

This is contracdictory. info Black on white background or whiteon black ?

No, Wendy's instructions will gie you what Mike describes - her firsts tep after loading grabs the area you want to mask out, so black, then she inverts and fills the area you want to keep with white.

fc633809

Sorry for double comment .

Was a lot of work (trees ! aaaargh !)

but IT WORKED ! Thank you guys.