Difference between revisions of "3D Objects"

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''based on [http://forums.wolfire.com/viewtopic.php?f=16&t=11227 this] forum post by member Markuss.''
+
== Introduction ==
There is a linked .zip file attached to the forum post. it can be found here:
+
Phoenix uses .xml files to store information about what textures a certain model should use as well as other information such as what shader it should use. This is the file you choose when loading an object. Here is an example object .xml file:
http://www.markstockton.com/misc/Guide/Examples.zip
 
 
 
==Basics==
 
In Overgrowth 3D models use the [http://en.wikipedia.org/wiki/Wavefront_.obj_file .OBJ format] but the material counter-part (.MTL) is not used, instead an “object properties file” stores links to model and texture files as well as some other information. This is the file you choose when loading an object, it uses the .XML format and can be read/created in any text editor:
 
  
 
<pre>
 
<pre>
 
<?xml version="1.0" ?>
 
<?xml version="1.0" ?>
 
<Object>
 
<Object>
<Model>Data/Custom/Markuss/Examples/Models/SimpleObject.obj</Model>
+
<Model>Data/Mods/example_mod/Data/Models/SimpleObject.obj</Model>
<ColorMap>Data/Custom/Markuss/Examples/Textures/SimpleObject_Color.tga</ColorMap>
+
<ColorMap>Data/Mods/example_mod/Data/Textures/SimpleObject_Color.tga</ColorMap>
<NormalMap>Data/Custom/Markuss/Examples/Textures/Blank_Norm.tga</NormalMap>
+
<NormalMap>Data/Mods/example_mod/Data/Textures/Blank_Norm.tga</NormalMap>
   <ShaderName>cubemap</ShaderName>
+
   <ShaderName>envobject #TANGENT</ShaderName>
 
<MaterialPath>Data/Materials/default.xml</MaterialPath>
 
<MaterialPath>Data/Materials/default.xml</MaterialPath>
 
</Object>
 
</Object>
 
</pre>
 
</pre>
  
===Tags===
+
All object .xml files that ship with the game are located in ../Overgrowth/Data/Objects/.
'''<Model>''' - links to the model file (.OBJ)
+
 
 +
=== Model and Texture Requirements ===
 +
* Only triangles in models
 +
* Models use the Wavefront .obj format
 +
* Textures need to be square
 +
* Texture resolution need to be a power of two (32x32, 64x64, 128x128 and so on)
 +
* The .tga format is recommended for textures, but .png and .tif work also.
  
'''<ColorMap>''' - links to the color texture file (.TGA .TIF)
+
==== Converting normal maps ====
 +
[[File:Convert_normals_tutorial.mp4|400px|thumb|right|Video tutorial on how to convert normal maps in GIMP]]
 +
The normal maps that you get from some applications might not be instantly usable in the Phoenix engine without some edits. For instance, if you are using an object space normal map from Substance Designer you need to do this:
  
'''<NormalMap>''' - links to the [http://blog.wolfire.com/2009/10/character-normal-maps/ normal map] texture file (.TGA .TIF)
+
# Invert the blue channel
 +
# Swap blue and green channels
  
'''<ShaderName>''' - refers to internal shader file (.FRAG .VERT, in Data/GLSL/), defines how object is rendered.
+
You can do this in Photoshop, Substance Designer, or GIMP. Note that Gimp does not work well with alpha channels. On the right is a tutorial on how to convert object space normal maps into tangent space using GIMP.
  
'''<MaterialPath>''' - links to internal material file (.XML), defines sound made by hitting the object.
+
== Object .xml File ==
 +
The object .xml files contain all information about a single object (model) that can be spawned in the engine. This aims to be a full reference over all tags and flags that can be used in an object .xml.
  
====Additional tags====
+
=== Tags ===
 +
{| class="wikitable"
 +
|-
 +
! Tag !! Example use !! Description
 +
|-
 +
! Model
 +
| <pre><Model>Data/Models/MyModel.obj</Model></pre>
 +
|| path to the model file (.obj)
 +
|-
 +
! ColorMap
 +
| <pre><ColorMap>Data/Textures/MyColorMap.tga</ColorMap></pre>
 +
|| path to the color texture file (.tga, .tif or .png)
 +
|-
 +
! NormalMap
 +
| <pre><NormalMap>Data/Textures/MyNormalMap.tga</NormalMap></pre>
 +
|| Path to the normal map texture file (.tga, .tif or .png)
 +
|-
 +
! ShaderName
 +
| <pre><ShaderName>envobject #TANGENT #KEEP_SPEC</ShaderName></pre>
 +
|| What shader to use, see [[#Shaders|shaders]] for more information
 +
|-
 +
! MaterialPath
 +
| <pre><MaterialPath>Data/Materials/DirtyRock.xml</MaterialPath></pre>
 +
|| Path to the material to use, see [[#Materials|materials]] for more information.
 +
|-
 +
! WeightMap
 +
| <pre><WeightMap>Data/Textures/Environments/Rocks/granite_vine_rocks/granite_vine_boulder_overgrown_w.tga</WeightMap></pre>
 +
|| Path to a black and white texture used for determining where each detail texture should be used. Required when using the detailmap4 [[#Shaders|shader]].
 +
|-
 +
! TranslucencyMap
 +
| <pre><TranslucencyMap>Data/Textures/Environments/cat_props/banner_t.tga</TranslucencyMap></pre>
 +
|| Path to a color texture used for translucency, meaning light that shines through the object. Adds its color to the surface multiplied by the amount of light it receives, this effect ignores the normal of the surface, so if one side receives light from for instance the sun, the other side will also get the color added. If unspecified it defaults to 0.0 (no translucency) across the entire surface. Optional when using the plant [[#Shaders|shader]].
 +
|-
 +
! WindMap
 +
| <pre><WindMap>Data/Textures/Environments/cat_props/banner_w.tga</WindMap></pre>
 +
|| Path to a black and white texture used to define the intensity of a vertex wind effect. If unspecified it defaults to 1.0 (active) across the entire surface. Optional when using the plant [[#Shaders|shader]].
 +
|-
 +
! DetailMaps
 +
| <pre><DetailMaps>
 +
    <DetailMap colorpath="Data/Textures/Terrain/DetailTextures/gray_rock.tga" normalpath="Data/Textures/Terrain/DetailTextures/gray_rock_normal.tga" materialpath="Data/Materials/rocks.xml" />
 +
    ...
 +
</DetailMaps></pre>
 +
|| Contains exactly 4 <DetailMap> tags describing textures and materials that will be tiled across the model using the <WeightMap> tag's texture. Required when using the detailmap4 [[#Shaders|shader]].
 +
|-
 +
! DetailObjects
 +
| <pre><DetailObjects>
 +
    <DetailObject obj_path="Data/Objects/Plants/Groundcover/Groundcover1.xml" weight_path="Data/Textures/Environments/Rocks/granite_vine_rocks/granite_vine_boulder_overgrown_vine_mask.tga" normal_conform="0.9" density="10" min_embed="0" max_embed="0.4" min_scale="0.7" max_scale="2" view_distance="40" jitter_degrees="10" overbright="0" />
 +
</DetailObjects></pre>
 +
|| Contains one or more <DetailObject> tags, each describing how to randomly distribute some object across the surface. Can be used for grass, small rocks etc.
 +
|-
 +
! flags
 +
| <pre><flags no_collision=true double_sided=true/></pre>
 +
|| Used to set boolean values on the object (see [[#Flags|flags]])
 +
|-
 +
! GroundOffset
 +
| <pre><GroundOffset>0.5</GroundOffset></pre>
 +
|| Moves the object up/down by the set amount when the object is created
 +
|}
  
'''<flags no_collision>''' - turns physics calculations on/off, true = off.
+
==== Deprecated tags ====
 +
These tags are deprecated and should not be used.
  
''NOTE:''
+
{| class="wikitable"
 +
|-
 +
! Tag !! Example use !! Description
 +
|-
 +
! ShaderPath
 +
| <pre><ShaderPath>Data/GLSL/cubemapobj</ShaderPath></pre>
 +
|| path to the shader to use (.frag & .vert), replaced by ShaderName
 +
|}
  
''“<ShaderName>” used to be “<ShaderPath>” and contained the full link instead of just the file name, expect similar update for “<MaterialPath>”.''
+
==== Materials ====
 +
These are the materials that can be assigned to objects using the <code><MaterialPath></code> [[#Tags|tag]]. You can find the materials in <code>../Overgrowth/Data/Materials/</code>. The material affects what particles spawn when a character runs on the surface, what sound footsteps make on the surface, how easily weapons stick in the surface, and more.
  
''Look at the example plant object for usage of the <flags no_collision> tag.''
+
* default
 +
* dirt
 +
* dirtytock
 +
* drygrass
 +
* grass
 +
* gravel
 +
* ice
 +
* rock
 +
* rocks
 +
* sand
 +
* snow
 +
* wood
  
===Model and Texture Requirements===
+
=== Flags ===
[[Image:SimpleObject.jpg|thumb|Simple object and texture UV layout]]
+
Flags are entered as boolean attributes ("true" or "false") in a [[#Tags|tag]] called "flags" under the "Object" tag. All flags have a default value of false.
  
Models need to be constructed from squares and triangles only, so textures need to be square and not just “powers of 2”. (512x512 or 1024x1024 not 512x1024 or 1024x2048)
+
{| class="wikitable"
 +
|-
 +
! Flag !! Description
 +
|-
 +
! no_collision
 +
| Disables physics collisions with this object.
 +
|-
 +
! double_sided
 +
| The backsides of the object gets rendered as well.
 +
|-
 +
! bush_collision
 +
| Makes the object give some resistance when passed through while the object wobbles a bit and generates leaf particles.
 +
|}
  
==Alternative object System==
+
==Collision/Physics Objects==
The engine automatically generates a simplified physics object and uses the object’s UV layout to place the shadow maps, these can be overridden by providing alternative .OBJ files that contain the desired information. These objects are placed in the same folder and share the same name as the original .OBJ file with a suffix to tell the engine what data they hold:
+
The engine automatically generates a simplified physics object from your model but this can be overridden by providing an alternative .OBJ file. The file is placed in the same folder and shares the same name as the original .OBJ file with a suffix:
  
 
===Suffixes===
 
===Suffixes===
'''YourObject_COL.obj''' - contains simplified geometry for physics calculations
+
[[Image:PhysicsObject.jpg|thumb|Physics mesh should be in the same place as the render mesh]]
 
+
[[Image:HullObject.jpg|thumb|Hull mesh should be in the same place as the render mesh]]
'''YourObject.obj_UV2''' - contains same object but with no overlapping UVs
+
{| class="wikitable"
 
+
|-
'''YourObjectHULL.obj''' - same as _COL but has extra info, used with weapons
+
! Suffix !! Description
 
+
|-
''NOTE:''
+
! <span style="color: gray">YourObject</span>_COL.obj
 
+
| Contains simplified geometry for physics calculations.
''The suffix formats are inconsistent, _COL is placed before the file extension while _UV2 is place after, and HULL doesn’t even have an underscore to separate it from the file name!''
+
|-
 
+
! <span style="color: gray">YourObject</span>HULL.obj
===Physics objects (_COL)===
+
| Same as _COL but has extra info, used for weapons.
[[Image:PhysicsObject.jpg|thumb|Physics mesh should be placed on top of the render mesh]]
+
|}
  
Simplified geometry such as boxes an cylinders which are used for collision detection, they are aligned to your object based on “relative position” in your 3D program so you should place the physics mesh on top of your render mesh upon export.
+
Note that HULL doesn’t have an underscore to separate it from the file name!
  
===Shadow UV objects (_UV2)===
+
===Physics objects (_COL)===  
[[Image:UVObject.jpg|thumb|Color texture UVs left, shadow UVs right, each face needs its own UV space]]
+
Simplified geometry such as boxes and cylinders which are used for collision detection, they are aligned to your object based on “relative position” in your 3D program so you should place the physics mesh on top of your render mesh upon export.
  
These objects tell the engine how to place the shadow map on the rendered object if the original UV layout isn’t appropriate, the shadow maps require UV layouts with no over-lapping faces, this can usually be achieved using the “automatic unwrapping” tools found in most 3D applications.
+
===Hull objects (HULL)===  
 
 
===Hull objects (HULL)===
 
[[Image:HullObject.jpg|thumb|Hull objects are placed over render mesh like physics objects]]
 
 
They are very similar to physics objects but are used for items and weapons, the only difference is that they contain a free-floating triangle which defines the object’s center of gravity.
 
They are very similar to physics objects but are used for items and weapons, the only difference is that they contain a free-floating triangle which defines the object’s center of gravity.
  
 +
== Shaders ==
 +
Overgrowth uses an "uber shader" approach to shader management, which means that there is one huge shader that almost everything in the game uses. So instead of choosing a shader for your object, you can set "flags" with your object that the game will use to change how it's rendered.
  
==Items and Weapons==
+
The flags are put in the <ShaderName> tag after the shader name. Here is an example:
[[Image:Weapons.jpg|thumb|Example weapons, handles show the location of characters hands]]
 
 
 
Items and Weapons are aligned to the character based on their position relative to the center of the scene in your 3D app, you should load the .obj files of the example objects for reference. To make an object “pick-up-able” you need another .XML file that you load in place of the regular object properties file, it stores the info needed that is not defined in the regular object properties file:
 
 
 
<pre>
 
<?xml version="1.0" ?>
 
<item>
 
    <type>weapon</type>
 
    <appearance obj_path = "Data/Custom/Markuss/Examples/1-Handed.xml"/>
 
    <grip ik_attach = "rightarm"
 
          anim = "Data/Animations/r_dogweapongrip.anm"/>
 
    <physics mass = "1 kg"/>
 
</item>
 
</pre>
 
Item properties file
 
 
 
===Tags===
 
'''<type>''' - defines what type of item the object is.
 
 
 
'''<appearance obj_path>''' - links to the regular object definition file.
 
  
'''<grip ik_attach anim>''' - defines what bone the object is attached to, links to an animation file.
+
<ShaderName>envobject #TANGENT #KEEP_SPEC</ShaderName>
  
'''<physics mass>''' - changes the pitch(?) of the sound made by the object hitting things.
+
"#TANGENT" and "#KEEP_SPEC" in this example are flags.
  
'''<anim_override idle>''' - overrides the idle animation of a character holding the item.
+
There are two texture maps that are required for an object to be loaded in the engine. Those are the '''ColorMap''' and the '''NormalMap''' textures. Some flags allow you to use more than these two required textures, and some flags change how the required textures are used. '''TODO:''' Are there any default textures that can be used and what are they?
  
''NOTE:''
+
Here is the channel designations of the ColorMap and NormalMap textures:
  
''Not sure what the animation file in <grip ik_attach anim> does.''
+
<u>'''ColorMap'''</u><br />
 +
'''RGB''' - Color<br />
 +
'''A''' - Reflectivity
  
''<anim_override idle> is only used for 2-handed weapons at the moment.''
+
<u>'''NormalMap'''</u><br />
 +
'''RGB''' - Normal<br />
 +
'''A''' - Color tint mask
  
''NOTE:''
+
Any deviation from these designations or new textures caused by any flag in the table below can be seen in the ''Channel/Texture Changes'' column.
  
''There is a bug that makes weapons turn invisible when loading levels with them already in it, you can fix this by having the “regular-object" version somewhere in the level as well.''
+
{| class="wikitable"
 +
|-
 +
! Tag !! Channel/Texture Changes !! Description
 +
|-
 +
! #TANGENT
 +
|
 +
|| The normal map is used as an object space normal map by default, with this flag it's used as a tangent space normal map instead.
 +
|-
 +
! #KEEP_SPEC
 +
|
 +
<u>'''NormalMap'''</u><br />
 +
'''A''' - Smoothness
 +
|| Instead of using the alpha channel of the normal map as a color tint mask, as is the default, that channel is used as a smoothness map. The object can still be tinted, you just can't control what parts get tinted.
 +
|-
 +
! #DETAILMAP4
 +
|
 +
<u>'''WeightMap'''</u><br />
 +
'''R''' - The first detail texture<br />
 +
'''G''' - The second detail texture<br />
 +
'''B''' - The third detail texture
  
==Shaders==
+
<u>'''DetailMap colorpath'''</u><br />
'''Cubemap''' – closest thing to a “standard shader”, it has a cube-map based on the sky texture and a specular shine, the visibility of the cube map and shine is controlled with color texture’s alpha channel, white = fully reflective and shiny. Similarly, the normal-map texture’s alpha channel controls where color tinting happens, white = full effect. The cube map’s visibility is inversely affected by the brightness of the texture, you should make the color texture close to black for materials that are reflective such as chrome and glass.
+
'''RGB''' - Color
  
'''CubemapObj''' - same as Cubemap but uses object-space normal maps instead of tangent space.
+
<u>'''DetailMap normalpath'''</u><br />
 +
'''RGB''' - Normal
 +
|| Allows for repeating up to 4 different textures over a model so it looks more detailed up close. This also means you can scale the model up or down with less obvious texture stretching.
  
'''CubemapItem''' - same as Cubemap but the shine is sharper.
+
* The WeightMap is used to decide which DetailMap texture to put where on the object
 +
* Each DetailMap has its own color texture, normal texture and material
 +
* See the [[#Tags|tags]] heading for information about how to specify the DetailMaps
 +
|-
 +
! #BASE_TANGENT
 +
|
 +
|| '''TODO:''' What does this do?
 +
|-
 +
! #AXIS_UV
 +
|
 +
|| '''TODO:''' What does this do?
 +
|-
 +
! #AXIS_BLEND
 +
|
 +
|| '''TODO:''' What does this do?
 +
|-
 +
! #NO_DECALS
 +
|
 +
|| No decals shows up on this object.
 +
|-
 +
! #WHY_DOES_THIS_WORK
 +
|
 +
|| '''TODO:''' What does this do?
 +
|-
 +
! #INVISIBLE
 +
|
 +
|| This object will not be rendered.
 +
|-
 +
! #ALPHA
 +
|
 +
<u>'''ColorMap'''</u><br />
 +
'''A''' - Transparency
 +
|| [[Image:CubemapAlpha.jpg|thumb|#ALPHA flag in action]]
 +
Makes the alpha channel of the ColorMap work as transparency instead of reflectivity
 +
|-
 +
! #PLANT
 +
|
 +
<u>'''ColorMap'''</u><br />
 +
'''A (reflectivity)''' - No effect
  
'''CubemapObjItem''' - object-space version of CubemapItem.
+
<u>'''NormalMap'''</u><br />
 +
'''A (color tint mask)''' - No effect
  
[[Image:CubemapAlpha.jpg|thumb|CubemapAlpha]]
+
<u>'''WindMap'''</u><br />
'''CubemapAlpha''' - has transparency controlled by the color texture’s alpha channel, cube map and shine are controlled by the normal-map texture’s alpha channel instead. CubemapAlpha has depth sorting issues with other transparent objects, enabling anti-aliasing fixes this somewhat.
+
'''R''' - Wind intensity<br />
  
'''CubemapObjChar''' - used for characters, shine is sharp, uses object space normals. There is no tangent-space version of CubemapObjChar and no object-space version of CubemapAlpha at the moment.
+
<u>'''TranslucencyMap'''</u><br />
 +
'''RGB''' - Translucency color<br />
 +
|| [[Image:Translucency.jpg|thumb|#PLANT flag in action together with the #ALPHA flag]]
 +
* Enables use of a WindMap which makes the object move in the wind
 +
* Enables use of a TranslucencyMap which makes it look like light can shine through the surface
 +
* Disables reflectivity
 +
* Disables color tint mask
 +
|-
 +
! #WATER
 +
|
 +
|| '''TODO:''' What does this do?
 +
|-
 +
! #METALNESS_PBR
 +
|
 +
<u>'''Colormap'''</u><br />
 +
'''A''' - Metalness<br />
  
[[Image:Translucency.jpg|thumb|Translucency (Plant Shader)]]
+
<u>'''Normalmap'''</u><br />
'''Plant''' - has transparency like CubemapAlpha but no cube map/shine. Translucency texture increases the brightness of the object while ignoring diffuse lighting, black = no effect. Wind texture defines intensity of a vertex ripple effect, black = no ripple. Both textures are linked in the object definition file using the <TranslucencyMap> and <WindMap> tags.
+
'''A''' - Roughness<br />
  
==Materials==
+
|| With this shader tag, you can make PBR objects in Overgrowth!
[[Image:Materials.jpg|thumb|Sound tiles]]
+
|}
These are the sounds made and the particles emitted when you hit an object. I’ve set up some tiles for you to walk on to preview each material, here is a list:
 
  
: Cloth_Fabric
+
=== Color Tint Mask ===
: Cloth_Leather
+
This mask is located in the alpha channel of the normal map, and determines what parts of the object should be tinted when using the [[Editor_Interface#Color_Picker|color picker]]. Black parts are not affected, the brighter the texel the more it is affected by tinting.
: Default
 
: Dirt
 
: DirtyRock
 
: Drygrass
 
: Grass
 
: Gravel
 
: Rock
 
: Rocks
 
: Sand
 
: Snow
 
: Wood
 
  
Note that some of these don’t emit particles.
+
== See also==
 +
* [[Custom Characters]]
 +
* [[Custom Weapons & Items]]

Latest revision as of 22:12, 16 July 2023

Introduction

Phoenix uses .xml files to store information about what textures a certain model should use as well as other information such as what shader it should use. This is the file you choose when loading an object. Here is an example object .xml file:

<?xml version="1.0" ?>
<Object>
	<Model>Data/Mods/example_mod/Data/Models/SimpleObject.obj</Model>
	<ColorMap>Data/Mods/example_mod/Data/Textures/SimpleObject_Color.tga</ColorMap>
	<NormalMap>Data/Mods/example_mod/Data/Textures/Blank_Norm.tga</NormalMap>
  	<ShaderName>envobject #TANGENT</ShaderName>
	<MaterialPath>Data/Materials/default.xml</MaterialPath>
</Object>

All object .xml files that ship with the game are located in ../Overgrowth/Data/Objects/.

Model and Texture Requirements

  • Only triangles in models
  • Models use the Wavefront .obj format
  • Textures need to be square
  • Texture resolution need to be a power of two (32x32, 64x64, 128x128 and so on)
  • The .tga format is recommended for textures, but .png and .tif work also.

Converting normal maps

Video tutorial on how to convert normal maps in GIMP

The normal maps that you get from some applications might not be instantly usable in the Phoenix engine without some edits. For instance, if you are using an object space normal map from Substance Designer you need to do this:

  1. Invert the blue channel
  2. Swap blue and green channels

You can do this in Photoshop, Substance Designer, or GIMP. Note that Gimp does not work well with alpha channels. On the right is a tutorial on how to convert object space normal maps into tangent space using GIMP.

Object .xml File

The object .xml files contain all information about a single object (model) that can be spawned in the engine. This aims to be a full reference over all tags and flags that can be used in an object .xml.

Tags

Tag Example use Description
Model
<Model>Data/Models/MyModel.obj</Model>
path to the model file (.obj)
ColorMap
<ColorMap>Data/Textures/MyColorMap.tga</ColorMap>
path to the color texture file (.tga, .tif or .png)
NormalMap
<NormalMap>Data/Textures/MyNormalMap.tga</NormalMap>
Path to the normal map texture file (.tga, .tif or .png)
ShaderName
<ShaderName>envobject #TANGENT #KEEP_SPEC</ShaderName>
What shader to use, see shaders for more information
MaterialPath
<MaterialPath>Data/Materials/DirtyRock.xml</MaterialPath>
Path to the material to use, see materials for more information.
WeightMap
<WeightMap>Data/Textures/Environments/Rocks/granite_vine_rocks/granite_vine_boulder_overgrown_w.tga</WeightMap>
Path to a black and white texture used for determining where each detail texture should be used. Required when using the detailmap4 shader.
TranslucencyMap
<TranslucencyMap>Data/Textures/Environments/cat_props/banner_t.tga</TranslucencyMap>
Path to a color texture used for translucency, meaning light that shines through the object. Adds its color to the surface multiplied by the amount of light it receives, this effect ignores the normal of the surface, so if one side receives light from for instance the sun, the other side will also get the color added. If unspecified it defaults to 0.0 (no translucency) across the entire surface. Optional when using the plant shader.
WindMap
<WindMap>Data/Textures/Environments/cat_props/banner_w.tga</WindMap>
Path to a black and white texture used to define the intensity of a vertex wind effect. If unspecified it defaults to 1.0 (active) across the entire surface. Optional when using the plant shader.
DetailMaps
<DetailMaps>
    <DetailMap colorpath="Data/Textures/Terrain/DetailTextures/gray_rock.tga" normalpath="Data/Textures/Terrain/DetailTextures/gray_rock_normal.tga" materialpath="Data/Materials/rocks.xml" />
    ...
</DetailMaps>
Contains exactly 4 <DetailMap> tags describing textures and materials that will be tiled across the model using the <WeightMap> tag's texture. Required when using the detailmap4 shader.
DetailObjects
<DetailObjects>
    <DetailObject obj_path="Data/Objects/Plants/Groundcover/Groundcover1.xml" weight_path="Data/Textures/Environments/Rocks/granite_vine_rocks/granite_vine_boulder_overgrown_vine_mask.tga" normal_conform="0.9" density="10" min_embed="0" max_embed="0.4" min_scale="0.7" max_scale="2" view_distance="40" jitter_degrees="10" overbright="0" />
</DetailObjects>
Contains one or more <DetailObject> tags, each describing how to randomly distribute some object across the surface. Can be used for grass, small rocks etc.
flags
<flags no_collision=true double_sided=true/>
Used to set boolean values on the object (see flags)
GroundOffset
<GroundOffset>0.5</GroundOffset>
Moves the object up/down by the set amount when the object is created

Deprecated tags

These tags are deprecated and should not be used.

Tag Example use Description
ShaderPath
<ShaderPath>Data/GLSL/cubemapobj</ShaderPath>
path to the shader to use (.frag & .vert), replaced by ShaderName

Materials

These are the materials that can be assigned to objects using the <MaterialPath> tag. You can find the materials in ../Overgrowth/Data/Materials/. The material affects what particles spawn when a character runs on the surface, what sound footsteps make on the surface, how easily weapons stick in the surface, and more.

  • default
  • dirt
  • dirtytock
  • drygrass
  • grass
  • gravel
  • ice
  • rock
  • rocks
  • sand
  • snow
  • wood

Flags

Flags are entered as boolean attributes ("true" or "false") in a tag called "flags" under the "Object" tag. All flags have a default value of false.

Flag Description
no_collision Disables physics collisions with this object.
double_sided The backsides of the object gets rendered as well.
bush_collision Makes the object give some resistance when passed through while the object wobbles a bit and generates leaf particles.

Collision/Physics Objects

The engine automatically generates a simplified physics object from your model but this can be overridden by providing an alternative .OBJ file. The file is placed in the same folder and shares the same name as the original .OBJ file with a suffix:

Suffixes

Physics mesh should be in the same place as the render mesh
Hull mesh should be in the same place as the render mesh
Suffix Description
YourObject_COL.obj Contains simplified geometry for physics calculations.
YourObjectHULL.obj Same as _COL but has extra info, used for weapons.

Note that HULL doesn’t have an underscore to separate it from the file name!

Physics objects (_COL)

Simplified geometry such as boxes and cylinders which are used for collision detection, they are aligned to your object based on “relative position” in your 3D program so you should place the physics mesh on top of your render mesh upon export.

Hull objects (HULL)

They are very similar to physics objects but are used for items and weapons, the only difference is that they contain a free-floating triangle which defines the object’s center of gravity.

Shaders

Overgrowth uses an "uber shader" approach to shader management, which means that there is one huge shader that almost everything in the game uses. So instead of choosing a shader for your object, you can set "flags" with your object that the game will use to change how it's rendered.

The flags are put in the <ShaderName> tag after the shader name. Here is an example:

<ShaderName>envobject #TANGENT #KEEP_SPEC</ShaderName>

"#TANGENT" and "#KEEP_SPEC" in this example are flags.

There are two texture maps that are required for an object to be loaded in the engine. Those are the ColorMap and the NormalMap textures. Some flags allow you to use more than these two required textures, and some flags change how the required textures are used. TODO: Are there any default textures that can be used and what are they?

Here is the channel designations of the ColorMap and NormalMap textures:

ColorMap
RGB - Color
A - Reflectivity

NormalMap
RGB - Normal
A - Color tint mask

Any deviation from these designations or new textures caused by any flag in the table below can be seen in the Channel/Texture Changes column.

Tag Channel/Texture Changes Description
#TANGENT The normal map is used as an object space normal map by default, with this flag it's used as a tangent space normal map instead.
#KEEP_SPEC

NormalMap
A - Smoothness

Instead of using the alpha channel of the normal map as a color tint mask, as is the default, that channel is used as a smoothness map. The object can still be tinted, you just can't control what parts get tinted.
#DETAILMAP4

WeightMap
R - The first detail texture
G - The second detail texture
B - The third detail texture

DetailMap colorpath
RGB - Color

DetailMap normalpath
RGB - Normal

Allows for repeating up to 4 different textures over a model so it looks more detailed up close. This also means you can scale the model up or down with less obvious texture stretching.
  • The WeightMap is used to decide which DetailMap texture to put where on the object
  • Each DetailMap has its own color texture, normal texture and material
  • See the tags heading for information about how to specify the DetailMaps
#BASE_TANGENT TODO: What does this do?
#AXIS_UV TODO: What does this do?
#AXIS_BLEND TODO: What does this do?
#NO_DECALS No decals shows up on this object.
#WHY_DOES_THIS_WORK TODO: What does this do?
#INVISIBLE This object will not be rendered.
#ALPHA

ColorMap
A - Transparency

#ALPHA flag in action

Makes the alpha channel of the ColorMap work as transparency instead of reflectivity

#PLANT

ColorMap
A (reflectivity) - No effect

NormalMap
A (color tint mask) - No effect

WindMap
R - Wind intensity

TranslucencyMap
RGB - Translucency color

#PLANT flag in action together with the #ALPHA flag
  • Enables use of a WindMap which makes the object move in the wind
  • Enables use of a TranslucencyMap which makes it look like light can shine through the surface
  • Disables reflectivity
  • Disables color tint mask
#WATER TODO: What does this do?
#METALNESS_PBR

Colormap
A - Metalness

Normalmap
A - Roughness

With this shader tag, you can make PBR objects in Overgrowth!

Color Tint Mask

This mask is located in the alpha channel of the normal map, and determines what parts of the object should be tinted when using the color picker. Black parts are not affected, the brighter the texel the more it is affected by tinting.

See also