Hedgehog Engine - Textures - Revision history

Justin113D: Added images

2025-07-12T09:13:39Z

Added images

← Older revision		Revision as of 09:13, 12 July 2025
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	* <code>BC3_UNORM</code> when transparent		* <code>BC3_UNORM</code> when transparent
	}}		}}
			[[File:HE1 Textures dif.png\|thumb\|<code>chr_sonic_body01_dif_HD.dds</code> from Sonic Generations]]
	Diffuse textures are color-transparency textures that are sampled directly for the base color of a material.		Diffuse textures are color-transparency textures that are sampled directly for the base color of a material.

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	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
	}}		}}
			[[File:HE1 Textures alp.png\|thumb\|<code>csc_etc_ty1_wind01_alp.dds</code> from Sonic Generations]]
	Opacity textures determine the transparency of a material.		Opacity textures determine the transparency of a material.

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	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
	}}		}}
			[[File:HE1 Textures fal.png\|thumb\|<code>chr_sonic_body01_fal_HD.dds</code> from Sonic Generations]]
			[[File:Falloff animation.gif\|thumb\|A camera rotating around Suzanne with a raw falloff factor. The diffuse texture is black, and the falloff texture is white]]
	Falloff textures change the color of the diffuse texture based on the viewing angle: The greater the angle between the camera and the surface of the model, the greater the influence.		Falloff textures change the color of the diffuse texture based on the viewing angle: The greater the angle between the camera and the surface of the model, the greater the influence.

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	==== Cubemap ====		==== Cubemap ====
			[[File:HE1 Textures cm.png\|thumb\|<code>chr_sonic_white_ref.dds</code> from Sonic Unleashed]]
	The most detailed, and probably best known type of reflection map. Uses 6 square areas, one for each side of a cube, to represent reflections from each axis.		The most detailed, and probably best known type of reflection map. Uses 6 square areas, one for each side of a cube, to represent reflections from each axis.

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	==== Spherical environment map ====		==== Spherical environment map ====
			[[File:HE1 Textures sem.png\|thumb\|<code>ghz_obj_kk1_giant_batabata_body_ref.dds</code> from Sonic Generations]]
			[[File:HE1 Textures sem animation.gif\|thumb\|A camera rotating '''around''' Suzanne with a spherical environment map]]
	The cheapest type of reflection, which always directly faces the camera.		The cheapest type of reflection, which always directly faces the camera.

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	==== Dual paraboloid environment map ====		==== Dual paraboloid environment map ====
			[[File:HE1 Textures dpem.png\|thumb\|<code>ghz_metal_yy1_sky_ref.dds</code> from Sonic Generations]]
	Effectively a full skybox composed of 2 spherical environment maps that cover the front and back of an environment.		Effectively a full skybox composed of 2 spherical environment maps that cover the front and back of an environment.

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	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
	}}		}}
			[[File:HE1 Textures ems.png\|thumb\|<code>boss_timeeater_light_ems_HD.dds</code> from Sonic Generations]]
	Emission textures make parts of a model emit light.		Emission textures make parts of a model emit light.

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	* The [[wikipedia:Blinn–Phong_reflection_model\|blinn phong lighting]] specular color in the RGB channels		* The [[wikipedia:Blinn–Phong_reflection_model\|blinn phong lighting]] specular color in the RGB channels
	* The environment map (reflection) influence in the alpha channel		* The environment map (reflection) influence in the alpha channel

			[[File:HE1 Textures spc rgb.png\|left\|thumb\|The color component of <code>chr_sonic_body01_spc_HD.dds</code> from Sonic Generations]]
			[[File:HE1 Textures spc a.png\|thumb\|The alpha component of <code>chr_sonic_body01_spc_HD.dds</code> from Sonic Generations]]

	<div style="clear: both"/>		<div style="clear: both"/>
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	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
	}}		}}
			[[File:HE1 Textures pow.png\|thumb\|<code>ghz_rock_sk1_wall01_pow.dds</code> from Sonic Generations]]
	Gloss textures determine the [[wikipedia:Blinn–Phong_reflection_model\|blinn phong]] lighting specular power.		Gloss textures determine the [[wikipedia:Blinn–Phong_reflection_model\|blinn phong]] lighting specular power.

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	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
	}}		}}
			[[File:HE1 Textures nrm.png\|thumb\|<code>ghz_rock_sk1_wall01_nrm.dds</code> from Sonic Generations]]
	Normal map textures are used for faking bumps and dents on a model to affect lighting, falloff, environment maps and similar.		Normal map textures are used for faking bumps and dents on a model to affect lighting, falloff, environment maps and similar.

Justin113D: Updated texture suffixes

2025-07-12T09:00:22Z

Updated texture suffixes

← Older revision		Revision as of 09:00, 12 July 2025
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	{{Texture Overview		{{Texture Overview
	\| suffix = _dif		\| suffix = <code>_dif</code>
	\| composition = RGBA		\| composition = RGBA
	\| encoding = * <code>BC1_UNORM</code> when opaque,		\| encoding = * <code>BC1_UNORM</code> when opaque,
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	{{Texture Overview		{{Texture Overview
	\| suffix = _alp		\| suffix = <code>_alp</code>, <code>_a</code>, often none at all
	\| composition = Grayscale		\| composition = Grayscale
	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
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	{{Texture Overview		{{Texture Overview
	\| suffix = _fal		\| suffix = <code>_fal</code>
	\| composition = Color		\| composition = Color
	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
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	{{Texture Overview		{{Texture Overview
	\| suffix = _ref		\| suffix = <code>_ref</code>, <code>_env</code>, <code>_cube</code>
	\| composition = RGBA		\| composition = RGBA
	\| encoding = * <code>BC1_UNORM</code> when opaque,		\| encoding = * <code>BC1_UNORM</code> when opaque,
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	{{Texture Overview		{{Texture Overview
	\| suffix = _ems		\| suffix = <code>_ems</code>, <code>_lum</code>
	\| composition = Color		\| composition = Color
	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
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	{{Texture Overview		{{Texture Overview
	\| suffix = _spc		\| suffix = <code>_spc</code>
	\| composition = RGBA		\| composition = RGBA
	\| encoding = <code>BC3_UNORM</code>		\| encoding = <code>BC3_UNORM</code>
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	{{Texture Overview		{{Texture Overview
	\| suffix = _pow		\| suffix = <code>_pow</code>
	\| composition = Grayscale		\| composition = Grayscale
	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>
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	{{Texture Overview		{{Texture Overview
	\| suffix = _nrm		\| suffix = <code>_nrm</code> (rarely <code>_norm</code>, <code>_nor</code>, <code>_nml</code>)
	\| composition = Color		\| composition = Color
	\| encoding = <code>BC1_UNORM</code>		\| encoding = <code>BC1_UNORM</code>

Justin113D: base page added

2025-07-12T08:54:35Z

base page added

New page

Hedgehog Engine 1 games limit themselves to a few texture types (with exceptions), which can make configuring materials difficult, as many shaders use certain types differently than what their name suggests.

Here is a list of all texture types and how they are most commonly used:

{| class="wikitable" style="margin:auto"
|+
!Type
!Primarily used with
!Occasionally used with
|-
|diffuse
|[[#Diffuse|Diffuse]]
|[[#Emission|Emission]]
|-
|opacity
|[[#Opacity|Opacity]]
|[[#Diffuse|Diffuse]]
|-
|reflection
|[[#Environment Map|Environment Map]]
|/
|-
|specular
|[[#Specular|Specular]]
|[[#Diffuse|Diffuse]], [[#Gloss|Gloss]]
|-
|gloss
|[[#Gloss|Gloss]]
|[[#Diffuse|Diffuse]], [[#Specular|Specular]]
|-
|normal
|[[#Normal map|Normal map]]
|/
|-
|displacement
|General use texture type
|[[#Falloff|Falloff]], [[#Emission|Emission]]
|}

=== File formats and encodings ===

Textures are always stored in [[wikipedia:DirectDraw_Surface|DDS]] files, of which the vast majority use some form of [https://learn.microsoft.com/en-us/windows/win32/direct3d10/d3d10-graphics-programming-guide-resources-block-compression block-compression] encoding. Only a handful are not compressed.

Since HE1 is programmed with [[wikipedia:Direct3D#Direct3D_9|Direct3D 9]], the number of available block compression encodings is limited to BC1, BC2 and BC3.

More info on DDS block compression can be found [https://learn.microsoft.com/en-us/windows/win32/direct3d11/texture-block-compression-in-direct3d-11 here].

{{notice
| type = note
| content = [https://gamebanana.com/mods/407367 The Direct3D 11 mod for Sonic Generations (PC)] by Skyth makes the game run on [[wikipedia:Direct3D#Direct3D_11|Direct3D 11]], which can read newer DDS encodings like BC4, BC5, BC6, BC7 and more.
}}

== Kinds of textures ==
The majority of textures used by materials are one of the following kind of textures.

=== Diffuse ===

{{Texture Overview
| suffix = _dif
| composition = RGBA
| encoding = * <code>BC1_UNORM</code> when opaque,
* <code>BC3_UNORM</code> when transparent
}}

Diffuse textures are color-transparency textures that are sampled directly for the base color of a material.

<div style="clear: both"/>

=== Opacity ===

{{Texture Overview
| suffix = _alp
| composition = Grayscale
| encoding = <code>BC1_UNORM</code>
}}

Opacity textures determine the transparency of a material.

Usually transparency is relayed to [[#Diffuse|Diffuse]] textures, and actual opacity textures are only used when special alpha compositing happens.

<div style="clear: both"/>

=== Falloff ===

{{Texture Overview
| suffix = _fal
| composition = Color
| encoding = <code>BC1_UNORM</code>
}}

Falloff textures change the color of the diffuse texture based on the viewing angle: The greater the angle between the camera and the surface of the model, the greater the influence.

Depending on the shader, the falloff color either gets mixed with the diffuse color or added to it.

Additionally, shaders with falloff colors or textures basically always come with a parameter that controls how the falloff factor gets calculated.

<div style="clear: both"/>

=== Environment map ===

{{Texture Overview
| suffix = _ref
| composition = RGBA
| encoding = * <code>BC1_UNORM</code> when opaque,
* <code>BC3_UNORM</code> when transparent
}}

Environment textures are used to project a fake reflection of the surroundings onto a model based on the viewing angle.

Some get layered on top of e.g. a diffuse texture, and have an alpha channel for their layer-transparency.

Depending on the shader, these have 3 different layouts:

==== Cubemap ====

The most detailed, and probably best known type of reflection map. Uses 6 square areas, one for each side of a cube, to represent reflections from each axis.

<div style="clear: both"/>

==== Spherical environment map ====

The cheapest type of reflection, which always directly faces the camera.

Also known as [https://learn.foundry.com/modo/content/help/pages/shading_lighting/shader_items/matcap.html MatCap] textures.

<div style="clear: both"/>

==== Dual paraboloid environment map ====

Effectively a full skybox composed of 2 spherical environment maps that cover the front and back of an environment.

Covers the same area as a cubemap but with less detail.

<div style="clear: both"/>

=== Emission ===

{{Texture Overview
| suffix = _ems
| composition = Color
| encoding = <code>BC1_UNORM</code>
}}

Emission textures make parts of a model emit light.

<div style="clear: both"/>

=== Specular ===

{{Texture Overview
| suffix = _spc
| composition = RGBA
| encoding = <code>BC3_UNORM</code>
}}

Specular textures contain 2 different maps:

* The [[wikipedia:Blinn–Phong_reflection_model|blinn phong lighting]] specular color in the RGB channels
* The environment map (reflection) influence in the alpha channel

<div style="clear: both"/>

=== Gloss ===

{{Texture Overview
| suffix = _pow
| composition = Grayscale
| encoding = <code>BC1_UNORM</code>
}}

Gloss textures determine the [[wikipedia:Blinn–Phong_reflection_model|blinn phong]] lighting specular power.

<div style="clear: both"/>

{{notice
| type = note
| content = Almost every Hedgehog Engine 1 game calculates the gloss factor differently, which may cause the same gloss texture to look different in each game.
}}

=== Normal Map ===

{{Texture Overview
| suffix = _nrm
| composition = Color
| encoding = <code>BC1_UNORM</code>
}}

Normal map textures are used for faking bumps and dents on a model to affect lighting, falloff, environment maps and similar.

See [[Normal mapping|normal mapping]] for reference.

<div style="clear: both"/>

{{notice
| type = note
| content = Compared to blender, the green channel is inverted. ([[Hedgehog Engine Blender I/O|HEIO]] corrects this on import/export)
}}