Making a custom breakable surface

Note:This so far has only been tested in Half-Life 2 in the 2009 branch of the Source Engine, but in other Source games that support DirectX 8/9, and where this entity is fully programmatically functional, this should still work.

Todo: Test with other surface properties

What you need

You will need:

• A VTF editor/maker (VTFEdit was used in the making of this tutorial, but VTEX can be used also.) to make the textures VTF files

• A VTF texture to represent the intact material

• A VTF texture with an alpha channel (8-bit for semi-transparent surfaces) to represent the damaged material

A mask for both textures is optional.

Handling the material/texture files

• After you've got your 2 masks and/or textures, place them in the appropriate game/mod materials directory (and whatever subfolders you wish to put them in) (e.g Half-Life 2/hl2/materials).

• Create 2 text documents in the same folder your VTFs are in, with each one having the same file name as a respective VTF. Make sure you have extensions visible and change the file extension to .vmt, or save the text documents as .vmt in whatever text editor you're using.

Note:It's good practice to name your materials (whatever)001a for the first frame then (whatever)001b for the second frame and so on when you are switching between said materials on a brush face(s) in game

The intact texture

After you have created the material/textures in the appropriate paths, copy, paste and fill the "(...)" enclosed strings with the paths to the respective VTF files into your intact material VMT:

"LightmappedGeneric"
{
	"$basetexture" "(VTF NAME HERE)"
	"$envmap" "env_cubemap"
	"$surfaceprop" "(Surface properties goes here, it's glass by default)"
	"$envmapmask" "(VTF MASK NAME GOES HERE)"
	"$translucent" 1
	"$multipass" 1
	"$nocull" 1
	"$crackmaterial" "(DAMAGED MATERIAL PATH GOES HERE)"

	"LightmappedGeneric_hdr_dx9"
	{
		"$envmaptint" "[.08 .08 .08]" 
	}
}

Note:If you are not using a texture mask, comment out (type // behind) the line $envmapmask is on.

Insert the appropriate paths where $basetexture, $envmapmask and $crackmaterial are specified

Save the VMT in the same folder as your first (intact) VTF file

The damaged texture

The damaged texture needs to have an alpha channel otherwise skybox/black texture will appear when the surface breaks.

Copy and paste the following code into your damaged material VMT

"ShatteredGlass"
{
	"$basetexture" "(VTF NAME GOES HERE)"
	"$detail" "(VTF NAME GOES HERE)"
	"$envmap" "env_cubemap"
	"$surfaceprop" "(Surface properties goes here, it's glass by default)"
	"$envmapmask" "(TEXTURE MASK GOES HERE)"
	"$translucent" 1
	"$basetexturetransform" "scale .7 .7"
	"$detailscale" 0.7
	"$unlitfactor" 0.0

	"ShatteredGlass_DX8"
	{
		"$unlitfactor" 0.3

		// This is roughly equal to the average value of envmapmask of the unbroken texture
		"$envmaptint" "{201 201 201}"
	}

	// On the low end, envmaptint + lightmap tint both use the average alpha value 
	"ShatteredGlass_DX7"
	{
		// This is roughly equal to the average value of alpha channel of the unbroken basetexture
		"$lightmaptint" "{128 128 128}"

		// This is roughly equal to the average value of envmapmask of the unbroken texture
		// times the average value of the alpha value of the unbroken base texture
		"$envmaptint" "{100 100 100}"

	}

	"$nocull" 1

	"Proxies"
	{
		"BreakableSurface"
		{
		}
	}
}

Note:If you are not using a texture mask, comment out (type // behind) the line $envmapmask is on.

End

Provided you have done everything right, you should now have a texture that works fully with the func_breakable_surf brush entity provided all except 1 side is Nodraw.

Modifications to the independent parameters (e.g $lightmaptint) can be made without any loss of functionality, however since func_breakable_surf is mostly used for glass, it has been optimised as such (hopefully).