Update mapping MapPicture

diff --git a/mapping-MapPicture.md b/mapping-MapPicture.md
index d0304a0948d9a0b2af3f38324e199dc38c40fd1d..3ca762ce329d0b53be99af227092dfd86065f084 100644 (file)
--- a/mapping-MapPicture.md
+++ b/mapping-MapPicture.md
@@ -5,15 +5,16 @@ Make your map sexy !
 Your map should include a preview picture. This picture will be visible from the game menu and from the servers vote screen.
 
 In order to do so:
-*  Load your map in the game
-*  Use the command `r_letterbox -1` in the console to turn off the HUD
+*  Load your map in the game and stay observer
+*  Use the command `r_letterbox -1` in the console to turn off the HUD (not `r_letterbox 1` as it'd add top and bottom borders)
 *  If your map has "waypoint" entities (like CTF or CTS maps), you can hide them with `cl_hidewaypoints 1`
+*  turn off jpeg compression with `scr_screenshot_jpeg 0` to avoid a double lossy compression (you'll have to compress it to jpg later)
 *  Take a nice screenshot with F12
 *  Go to your Xonotic user directory, on the `data/screenshot` subdirectory. Your user directory location depends on your operating system, more information [here](https://xonotic.org/faq/#config).
-*  Open the screenshot with an image editor, e.g. GIMP
-*  Crop it so that it has a 4:3 ratio
-*  Scale it to 512x512 px (weird but standard)
-*  Save it as a JPG file (~90% quality)
+*  Open the generated .tga screenshot with an image editor, e.g. GIMP
+*  Crop it so that it has a 4:3 ratio, e.g. if resolution is 1366x768 then crop it to 1024x768
+*  Scale it to 512x512 px (the resulting image should appear vertically stretched)
+*  Save it (export in Gimp) as a JPG file (~90% quality); other formats like tga and png aren't acceptable because they generally produce much bigger files
 *  Put it in the same location as the bsp file, with the same name (see next chapter for packaging rules).
 
 Original source of information: https://forums.xonotic.org/showthread.php?tid=6067&pid=75757#pid75757