View source for Zh/$phong

{{lang|$phong|title=冯氏反射}}[[Category:List of Shader Parameters|P]][[Category:VMT Lighting]]
[[File:Alyx phong closeup.jpg|thumb|200px|Phong shading provides Alyx's skin, hairband and lip highlights.]]

{{Shaderparam|$phong|since=Source 2006|shader1=VertexLitGeneric|shader2=LightmappedGeneric|shader3=WorldVertexTransition}} It provides [[Wikipedia:Diffuse_reflection|diffuse reflections]] at low intensity and [[Wikipedia:Specular_highlights|specular highlights]] at apex intensity, masked by a texture which control per-texel its intensity. For a full explanation, see [[Phong materials]].
{{Note|Phong shading for <code>LightmappedGeneric</code> and <code>WorldVertexTransition</code> is only available in {{csgobranch|4}}. It requires the material to be lit by the sunlight from a {{ent|env_cascade_light}} entity to work properly and uses the dynamic shadows generated by it as a mask on top of the traditional phong masking.}}
{{Note|Phong shading for <code>LightmappedGeneric</code> is also available in {{mapbase|4}}, but it is implemented differently.}}
==Syntax==

 $phong <[[bool]]>

{{note|All parameters in the following example must be specified in the material, otherwise Phong shading won't show up at all, except in {{insurgency|4}}.}}
:{{todo|Other games that don't require all phong parameters present (likely Portal 2 and up)}}
<syntaxhighlight lang=php>
VertexLitGeneric
{
	$phong 1

	$bumpmap				[texture]
	$phongexponent			5			// either/or
	$phongexponenttexture	[texture]	// either/or
	$phongboost				1.0
	$phongfresnelranges		"[0 0.5 1]"
}
</syntaxhighlight>


== Parameters ==
=== Masking ===
{{warning|There are some caveats regarding {{ent|$normalmapalphaenvmapmask}} and [[Glowing_Textures#.24selfillum|$selfillumfresnel]] when using {{ent|$phong}}!}}
* Using [[Glowing_Textures#.24selfillum|$selfillumfresnel]] '''without''' {{ent|$normalmapalphaenvmapmask}} will mask the {{ent|$envmap}} using the {{ent|$basetexture}}'s alpha channel.
* Using [[Glowing_Textures#.24selfillum|$selfillumfresnel]] '''with''' {{ent|$normalmapalphaenvmapmask}} will multiply the {{ent|$envmap}} by <code>0.0f</code>. Effectively disabling the effect!
* When '''not''' using [[Glowing_Textures#.24selfillum|$selfillumfresnel]]. The mask used for {{ent|$envmap}} will be the {{ent|$basetexture}}'s alpha channel '''unless''' {{ent|$normalmapalphaenvmapmask}} is also used.
* '''If''' {{ent|$normalmapalphaenvmapmask}} is used, the {{ent|$bumpmap}}'s alpha channel will be used for Phong masking. Using either <code>$basemapalphaphongmask</code> or <code>$basemapluminancephongmask</code> will override it.
<br>
{{MatParam|$bumpmap|texture|Phong requires mask. The [[alpha channel]] of a [[$bumpmap|bump map]] acts as a Phong mask by default.}}
{{MatParam|$basemapalphaphongmask|bool|Use {{ent|$basetexture}}'s [[alpha channel]] as the Phong mask instead of <code>$bumpmap</code>'s [[alpha channel]].
{{warning|Using this with {{ent|$normalmapalphaenvmapmask}} will override the mask used for {{ent|$envmap}} to be the contents of the {{ent|$basetexture}}'s alpha channel!}}
{{warning|{{gmod|4}} Using this with {{ent|$normalmapalphaenvmapmask}} and {{ent|$envmap}} renders in {{ent|$envmap}} and '''<code>$phong</code>''' be masked by both '''<code>$basemapalphaphongmask</code>''' alpha channel and {{ent|$normalmapalphaenvmapmask}} alpha channel.}} |since={{src07}}|shaders=VertexLitGeneric}}
{{MatParam|$basemapluminancephongmask|bool|Mask phong intensity based on the brightness of the <code>$basetexture</code>.
{{bug|Basetexture Luminance will replace the mask used for {{ent|$envmap}}, '''if''' {{ent|$normalmapalphaenvmapmask}} is used.}}
{{bug|Doesn't work in {{gmod|4}}.}}
|not={{gmod}}|since={{l4d}}|shaders=VertexLitGeneric}}
{{MatParam|$phongexponent|and=$phongexponent2|int|A global [[Phong materials#Phong mask and exponent texture|exponent]] value. Overrides an exponent mask if present.
: <code>$phongexponent2</code> is for <code>WorldVertexTransition</code>'s second material in {{csgobranch|4}}.}}
{{MatParam|$phongexponenttexture|texture|A per-texel exponent map. In an exponent map:
:* '''Red channel:''' Exponent mask (size of highlight, 0-255, where a value of 0 is a large highlight, 255 small.)
:* '''Green channel:''' Albedo tint mask (only if <code>$phongalbedotint 1</code>, 0-255, where a value of 0 is no tint, 255 full tint.)
:* '''Blue channel:''' Nothing.
:* '''Alpha channel:''' {{ent|$rimlight}} mask (only if '''<code>$rimmask 1</code>'''.)
:{{Note|<code>LightmappedGeneric</code> and <code>WorldVertexTransition</code> do not have support for <code>$phongexponenttexture</code>. You must use <code>$phongexponent</code> instead.}}|shaders=VertexLitGeneric}}
{{MatParam|$phongexponentfactor|float|Multiply the exponent from the <code>$phongexponenttexture</code> by this amount. {{tip| The default value of this parameter is <code>"0.0"</code>. However, a more reasonable default value would be <code>"149.0"</code>}}|only={{src13mp}}{{tf2}}|shaders=VertexLitGeneric}}
{{MatParam|$invertphongmask|bool|Invert the value of the phong mask.
{{bug|In {{as}}s and {{src13}}s Shadercode, using this parameter will invert the mask used for {{ent|$envmap}}, not the one used for <code>$phong</code>! }}
{{confirm| Is this the case for all branches?}}
|since={{src07}}|shaders=VertexLitGeneric}}
{{MatParam|$forcephong|bool|Force phong shading on phong-using materials even at low GPU levels when <code>mat_phong</code> is disabled.|since={{portal2}}|shaders=VertexLitGeneric}}
{{MatParam|$diffuseexp|float|Diffuse exponent used for dynamic lights only.
{{note|have this with {{ent|$halflambert}} greatly decrease it effect.}}|only={{L4ds}}|shaders=VertexLitGeneric, Infected}}
{{MatParam|$shinyblood|int|Derive phong mask from areas that are more red than others. Only when variation is disabled.|only={{L4ds}}|shaders=VertexLitGeneric, Infected}}
{{MatParam|$shinybloodexponent|int|Exponent for the above.|only={{L4ds}}|shaders=VertexLitGeneric, Infected}}

=== Brightness ===
{{MatParam|$phongboost|float|Phong brightness factor. Larger values create a more intense highlight, useful for surfaces like metal and glass.|shaders=VertexLitGeneric, LightmappedGeneric({{mapbase|only}})}}
{{MatParam|$phongfresnelranges|matrix|See [[Phong materials#Phong Fresnel ranges|Phong Fresnel ranges]]. Default is <code>"[0 0.5 1]"</code>.
:{{note|<code>$envmap</code> is also affected by these fresnel ranges if both it and Phong are enabled in a material.}}
:{{note| drives the x component of a phongwarptexture if specified.}}|shaders=VertexLitGeneric, LightmappedGeneric({{mapbase|only}})}}
{{MatParam|$phongdisablehalflambert|bool|Disables forced [[$halflambert|half-lambertian]] shading on Phong materials. {{note|This parameter is effectively forced on in {{csgobranch|4}} due to <code>$halflambert</code> being disabled.}}|since={{as}}|also={{Mapbase}}|shaders=VertexLitGeneric}}

=== Colors ===
{{MatParam|$phongalbedotint|bool|Tints the phong reflection by the color of the <code>$basetexture</code>. The amount of tint is defined by the green channel of <code>$phongexponenttexture</code>. A <code>$phongexponenttexture</code> must be specified in order for <code>$phongalbedotint</code> to work.
: {{Warning|<code>$phongalbedotint</code> cannot be used with <code>$phongtint</code>. The later will disable the effect.}}
: {{Note|<code>$phongalbedotint</code> works by multiplying the <code>$basetexture</code> over the reflection, without darkening the albedo. The reflection will get dimmer as a result, so account for this in the phong mask or with <code>$phongboost</code>.}}
: {{Note|<code>$phongalbedotint</code> will tint highlights by the original color of the <code>$basetexture</code> even when the material is tinted by <code>$color2</code> or <code>rendercolor.</code>}}|since={{src07}}|shaders=VertexLitGeneric}}
{{MatParam|$phongalbedoboost|float|Phong albedo overbrightening factor. Ranges 0-255.
: {{note| This will multiply the tint that is being applied to phong from $phongalbedotint.}}
: {{bug| This does not work when using [[$detail]]. }}|since={{csgo}}|shaders=VertexLitGeneric}}
[[File:Phongwarp example.png|thumb|200px|The Hunter without and with its <code>$phongwarptexture</code>, showing how it affects the Phong reflection.]]
{{MatParam|$phongtint|RGB matrix|Color tint of the phong reflection.
: {{Warning|This will override <code>$phongalbedotint</code> if both are used.}}
: {{note| Also tints {{ent|$rimlight}}}}|since={{src07}}|shaders=VertexLitGeneric}}
[[File:Phongwarp_coordinate_guide.png|thumb|200px|Breakdown of the $phongwarptexture: computed coordinates, texture and result]]
{{MatParam|$phongwarptexture|texture|Used to create an iridescence effect, as seen on Episode Two's [[npc_hunter|Hunters]].
: The highlight is multiplied with a texture. The coordinates of the sampled pixel are as follows:
:x: 1 - (distance to the center of the highlight)
:y: 1 - (fresnel component as computed by [[Phong materials#Phong Fresnel ranges|Phong Fresnel ranges]])
: {{note|Disables the initial phongfresnelranges masking}}
: {{bug|Does not work in {{l4d2|4}}.}}|since={{src07}}|shaders=VertexLitGeneric}}
[[File:Brush_phong.jpg|thumb|200px|Brush phong in {{csgo|2}} using tile/hr_t/inferno/tile_a. Note the complete absence of the reflection in the shaded area.]]

===Brush Shader Parameters {{csgobranch|only}}===
{{MatParam|$phongmaskcontrastbrightness|and=$phongmaskcontrastbrightness2|vector2|The first value controls the contrast level between light and dark areas in the mask, and the second value controls the overall brightness. 
: <code>$phongmaskcontrastbrightness2</code> is for <code>WorldVertexTransition</code>'s second material.
: {{todo|Find out the range of both values.}}|shaders=LightmappedGeneric, WorldVertexTransition}}
{{MatParam|$phongamount|and=$phongamount2|vector4|The first 3 values control the color tint, and the fourth value controls the brightness. The fourth value can go beyond 1, but affects the brightness of the whole texture, not just the highlight. 
: <code>$phongamount2</code> is for <code>WorldVertexTransition</code>'s second material.|shaders=LightmappedGeneric, WorldVertexTransition}}
{{MatParam|$phongbasetint|and=$phongbasetint2|float|Allows the <code>$basetexture</code> and/or <code>$basetexture2</code> to tint the color of the Phong highlight.|shaders=LightmappedGeneric, WorldVertexTransition}}

== 控制台命令 ==
{{IO|mat_phong|param=bool|禁用或启用冯氏反射。默认为 1。}}

== 另见 ==
* [[Phong materials]]
* {{ent|$envmap}} (environment map)
* {{ent|$lightwarptexture}}
* {{ent|$rimlight}}
* [https://tf2maps.net/threads/phong-on-brushes-the-hacky-way.26765 $Phong on brushes*: The Hacky Way (a TF2maps.net guide on how to fake $Phong on brushes for games prior to CS:GO)]
*[https://share.substance3d.com/libraries/6595 SubstancePainter Source Engine Complex Phong Shader]