# D2Mods Knowledge Base: Article 465
# Title: Overlay.txt
# URL: https://d2mods.info/forum/kb/viewarticle?a=465

Overlay.txt
		Written by: Desocupado

		Written on: Thu Jan 27, 2011 3:40 pm

		Last modified: Wed Oct 24, 2018 2:29 pm
		Views: 8911

		Description: By Desocupado, restyled by Ogodei

		Categories: File Guides (1.10 - 1.14)

			Overlay.txt file guide

This txt controls the overlay graphics. These graphics are usually associated with casting animations, auras, curses/buffs and states.

Used by:

States.txt

Skills.txt

 Missiles.txt

internally by the code

Overlay: This column defines the name the game will associate with your overlay in the related files.

Filename: The .dcc graphic file associated with the overlay. It is found within Data/Global/Overlays

Version: It states for which game version the overlay is. 0 for classic only, 100 for Expansion.

Frames: The game doesn't read this field, but rather the actual number of frames from the .dcc file.

Character: Unused. You can write on this field with no consequences at all.

PreDraw: It tells whether the overlay is shown behind characters or monsters.  0 if you want the overlay to be drawn in front of the units, 1, if you want the unit graphics to take precedence.

1ofN: Default value is 1 . This field is for random overlay states that may set the overlay to index+rand(1ofN). I have no idea how to use it.

Dir - Open- Beta: Default value ranges from 0 to 1 , but produces no noticeable effects. You can even wrtie on this field with no consequences at all.

Position Settings

NOTE: All values are in pixels.

Xoffset - Yoffset: As for the X axis, positive values will place the overlay to the left and negative values will place it to the right.

For what concerns the Y axis, positive values places the graphic below, and negative values will place it above the target base.

Height1- Height4: These values modify the placement on Y-axis according to the unit height value set in MonStats2.txt.

NOTE: If the value set in MonStats2.txt is 0, then it uses Height2. (Thanks to Nefarius for clarifying what heights are used for).
This is actually a index in an array. That refers to the four height columns in Overlays.txt

Height1, Height2, Height3, Height4

Players always use Height2

A special case, if you set OverlayHeight to 0 ( the value returned by D2Common.10090 is decremented by 1 ), the special case -1 will

use a height 75 (i.e. the default ).
NOTE: Tests have shown that Height4  is only used by Prime Evils.

Position Settings

AnimRate: It controls how fast the animation play. Tests have shown that this field controls how many frames of animation are played per 25 frames of time. i.e. number of frames per second.

LoopWaitTime: This column seems to be unused. Nefarius pointed out that it is used by the game for some overlays that loop only periodically.

NOTE: only itemgleam, multigleam, npcalert, gleamtest3 and gleamtest4 have values assigned via this field.

Transparency and Light Settings

Trans:

It changes the overlay blending mode accordingly to the value is set.

```
0 - Faded
1 - Half Solid with small black borders
2 - Entirely Solid with small black borders
3 - Entirely Solid without black borders (black = transparent)
4 - Darkened and Transparent (like a shadow)
5 - Entirely Solid with big black borders
6 - It looks like '2'...
7 - Whitened  and Entirely Solid with small black boarders (high gamma)
8 - Like '3' but it flickers
9 - It looks like '2'...
```

InitRadius: It seems to control the light radius increase per frame.

WARNING: Never set it to 0 or below or it will crash the game.

Radius: Controls the maximum light radius which must be bigger or equal to InitRadius.

NOTE: The Light radius only expands.

Red - Green - Blue: They control the color of the light radius.

Unknown Settings

Radius: The defaut value is 1. It produces no noticeable effects. You can even write on this field with no consequence if you want. The game reads the # of directions from the DCC file.

Note: Only 'vulturedemonfeathers' overlay have a value of 4.

LocalBlood: It is not used in vanilla, and becomes useable only if you edit data/color.txt and set the localblood global boolean to true. It will then replace blood colors with the entries from GreenBlood.dat (which is actually gray).

Note: In vanilla it's only used by two overlays 'durieldead_rear' and 'tentacleheadbloodripple'.

Recommended Readings

MagicMatze posted a nice guide on using overlays to display a custom messages back on 2004.

Also check the File Guides for:

States.txt

Skills.txt

Missiles.txt

Tips, Ideas and Suggestion

1 - You can add an overlay to almost any skill by using the 'castoverlay' column on skills.txt. You could even add the monster animation as an overlay and produce an illusion effect while it casts some spell.

2 - You can add overlays to the targets of some skills. This is done by adding the overlay to 'srvoverlay'. For example: vengeance could cause that neat overlay on 'extravengeance' easily, if you want.

3 - Some missiles hit functions allows overlays. The classic 10/X (charged bolt function) being the most prominent example.

4 - How the overlay is played depends on how it has been called. Usually only overlays used by states.txt are repeated.

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				[url=https://d2mods.info/forum/kb/viewarticle?a=465]Knowledge Base - Overlay.txt[/url]