Physmats

Placement and Configuration

Physmats (short for physical materials) define the physical properties of surfaces and objects the player interacts with, such as terrain, environmental assets, or destructible objects. These interactions include driving over, colliding with, shooting at, or destroying the materials.

The physical material configuration defines the following properties:

Passability: Specifies whether a surface or object can be traversed.
Interaction Effects: Determines the visual, audio, or gameplay effects triggered during player interaction.
Vehicle Behavior: Defines how each material type influences vehicle handling and response.

The physmat configuration file is located at: <project_name>/develop/gameBase/config/physmat.blk

File Structure

The general structure of the physmat configuration file is as follows:

PhysMats{          // Container block for all physical materials
  __DefaultParams{ // Default parameters applied to all physmats unless explicitly overridden
    a
    b
    ...
  }
  physmat1{}       // Individual physmat definition with its specific parameters
  physmat2{}
  ...
  physmatN{}
}

InteractPropsList{     // Configuration block for player interactions with physical materials
  visibilityCamera{    // Defines physmats that do not collide with the camera
    transparentCamera{ // A physmat excluded from camera collision
      en:b = no        // 'no' disables collision with the camera
    }
  }
  visibilityRay{      // Defines physmats that are transparent for ray tracing
                      // For example, through which tank markers should remain visible.
    transparentBeton{ // A physmat through which tank markers remain visible
      en:b = no       // 'no' disables collision with the tracing ray
    }
  }
  tankTrack{          // Defines physmats that interact with tank tracks
                      // All driveable physmats must be listed here
    default{          // Physmat entry
      fk:r = 1.0      // Friction coefficient multiplier; 1.0 is standard, values < 1 simulate slippery surfaces,
                      // e.g., setting '0.5' simulates ice.
      rollingFrictionK:r = 0.045  // Rolling friction coefficient; lower values reduce rolling resistance
                                  // Hard surfaces typically have lower values than soft ones
    }
  }
  wheel{              // Defines physmats that interact with vehicle wheels
                      // All driveable physmats must be listed here
    default{          // Physmat entry
      fk:r = 1.0      // Friction coefficient multiplier; 1.0 is standard, values < 1 simulate slippery surfaces,
                      // e.g., setting '0.5' simulates ice.
      rollingFrictionK:r = 0.03  // Rolling friction coefficient; lower values reduce rolling resistance
                                 // Hard surfaces typically have lower values than soft ones
    }
  }
}

Physmat Parameters

The following parameters are currently supported in physmat definitions. These are demonstrated using an example physmat named horse{}, which includes all known configurable properties:

horse{}: Name of the physical material. Must be unique within the configuration.
bf_class:t = "horse_class": Material class identifier. This acts as a tag used to reference the physmat in the InteractPropsList{} block.
color:c = 255,162,0,100: Debug render color in RGBA format. Typically used for visual debugging. Usage is currently uncommon.
isWater:b = 0: Specifies whether the material represents water. A value of 1 marks it as water.
isUnit:b = 1: Indicates whether the material represents a unit (e.g., a vehicle or character).

Aircraft-Specific Parameters

shakeMultiplier:r = 1: Multiplier affecting screen shake when aircraft interact with this material.
frictionMultiplier:r = 1: Friction multiplier applied to aircraft interactions.

Tank-Specific Parameters

dustFactor:r = 0.14: Controls the amount of dust that accumulates on tanks from this material.
mudFactor:r = 0.1: Controls the amount of mud that accumulates on tanks.
deformable_width:r = 0.05: Defines the deformation depth of terrain under tank tracks.
tankTracksTexId:i = 0: Likely specifies the texture ID used for track marks left by tanks.
resistanceK:r = 0.00035: Friction coefficient for tank movement over this material.
trackEffectsPreset:t = "soil": References a named preset from the trackEffectsPresets{} block in gameParams.blk. Defines the visual and audio effects triggered when a tank drives over this material.
trackDirtSpawnRateMult:r = 1.2: Multiplier that controls the rate of dirt or particle effects generated by tank tracks on this material.

Explosion and Impact Parameters

Important

The explosionPatch{} block is interchangeable with the explMat parameter. Only one of these should be specified per physmat. Specifying both is unsupported. If neither is defined, the client may crash. Details below.

Explosion Patch Parameters

These parameters define the visual and physical behavior of bomb or rocket explosions (typically from aircraft). When used, they replace the need for explMat.

explosionPatchShader:t = "explosion_patch": Presumed to define the decal shader for explosion effects. May involve both normal and diffuse maps. SDK did not reveal its effect.
explosionPatchTexture:t = "explosion_patch_rocks_n": Likely defines the normal map texture used for explosion decals. SDK did not reveal its effect.*
explosionPatchTexcoord:p4 = 0, 0, 1, 1: Presumably sets the texture atlas coordinates used for explosion decals. SDK did not reveal its effect.
explosionPatchHeightScale:r = 0.01: Likely controls the heightmap deformation scale applied to explosion decals. SDK did not reveal its effect.

Alternative Explosion Material

explMat:t = "default": References an explosion material defined in the explMat.blk file. This parameter is interchangeable with the explosion patch parameters above. Only one should be used; otherwise, the client will crash.

Explosion Effects

explosionWreckage:t = "rocks_expl": Defines the model used for debris or wreckage generated during explosions.
explosionFx:t = "ground_explosion_fx": Specifies the visual effect triggered during an explosion.

Physical Impact Modifiers

iak:r = 0.2: Impulse absorption coefficient. Accepts values in the range 0.0 to 1.0. 0 means no impulse is applied; 1 means full impulse is applied.
damage_k:r = 0.3: Multiplier for damage applied on impact.

Projectile Penetration Effects

pierceFxType:t = "ad_sand": Defines the effect triggered when a projectile penetrates the material without being stopped. This can be overridden for specific ammunition calibers.
pierceFxScale:p2 = 0.1, 0.2: Specifies the minimum and maximum scale for the pierceFxType effect. The default scale is 1.0. Can be overridden per ammunition type.

Gunfire Decal Parameters

This block defines visual and physical properties for decals and effects generated by gunfire impacts on physical materials.

Decal Textures

rendinst_colorMap:t = "explosion_patch_ground_c": Specifies the diffuse (albedo) texture used for gunfire decals. Transparency is determined by the alpha channel. If no alpha is present, the albedo defaults to black and a soft radial fade is applied, producing a dark circle.
rendinst_normalMap:t = "explosion_patch_n": Defines the normal map used for gunfire decals. Standard smoothness and metalness values are assumed unless otherwise overridden.

Decal Rendering Controls

The following optional parameters control which visual components of the decal are rendered. These are useful when selectively disabling certain effects such as color or normal influence:

writeAlbedo:b = no: Disables albedo (diffuse color) rendering. Useful when only normals are needed.
writeSmoothness:b = no: Disables the smoothness (roughness) channel rendering.
writeNormal:b = no: Disables normal map rendering.
writeMetal:b = no: Disables metalness rendering.
writeShadow:b = no: Disables shadow casting for the decal.

Impact Effects

hitFxType:t = "ad_sand": Specifies the visual effect triggered upon gunfire impact. This can be overridden for specific ammunition calibers.
hitFxScale:p2 = 0.1, 0.2: Sets the minimum and maximum scale for the hitFxType effect. Can also be overridden per ammo type.
breachMat:t = "steel": Defines the breach material type used when a projectile penetrates a vehicle. Common values include "steel" or "wood", used to apply appropriate decal effects.

Vehicle Interaction Parameters

shakeProps { period:p2 = 0.35, 0.7; power:p2 = 1, 1; mult:p2 = 0.5, 0.2; }

Controls wheel shake when tanks drive over this material.

period defines the frequency range of the shake.
power controls the intensity.
mult applies additional modulation.

arcadeProps { boost:r = 1.0; }

Affects the arcade-mode boost calculation for tanks interacting with this material.

Deprecated or Unused Parameters

The following parameters are considered obsolete or are replaced by other blocks:

sizeInCalibers:r = 2: Not currently used.
shakePeriod:p2 = 0.35, 0.7: Deprecated. Use shakeProps instead.
shakePower:p2 = 1.0, 1.0: Deprecated. Use shakeProps instead.
shakeMult:p2 = 0.5, 0.2: Deprecated. Use shakeProps instead.
arcadeBoostMult:r = 1.0: Deprecated. Use arcadeProps instead.

Mandatory Physmat Parameters for Render Instances

To reduce duplication, physmats are not divided into separate “prop” and “terrain” categories. As a result, all physmats are expected to include a common set of parameters, regardless of their intended use. While not all parameters are strictly required in every case, omitting key fields can result in missing effects or gameplay issues.

If minimal setup is required, the following parameters are empirically known to be mandatory to ensure correct behavior. This list is not exhaustive:

hitFxType:t = "ad_explosion_glass": Defines the particle effect triggered on impact. Without this parameter, the expected visual effect will not play.
hitFxScale:p2 = 0.1, 0.2: Specifies the scale range for the hit effect. If omitted, the effect will play at its default size, which may not suit the context.
explMat:t = "default" or explosion patch parameters: Required for explosion handling. If neither explMat nor explosionPatch parameters are defined, explosion effects (e.g., tank shell impacts) may fail or cause visual bugs.
tankTrack {} and wheel {} blocks: Define friction and rolling behavior for tracked and wheeled vehicles. If these blocks are missing, vehicles will not be able to traverse the physmat at all.

Overriding Physmat Parameters in Other Configurations

Physmat parameters are frequently overridden within the configurations of other game objects, such as landscapes, projectiles, or vehicles. This can lead to unexpected physmat behavior if overrides conflict with the base physmat settings.

If a physmat does not behave as intended, it is important to check related configurations for parameter overrides. Currently, the physmat system contains numerous such overrides, contributing to complexity and inconsistencies.

The long-term objective is to establish a clean, well-defined physmat configuration set that minimizes or eliminates the need for overrides, thereby simplifying maintenance and improving predictability.

Projectiles

Improper physmat behavior on projectiles most commonly appears in visual effects (FX). For example, a projectile may hit concrete, but trigger a glass impact effect, or the FX may appear at an incorrect scale (e.g. twice the intended size).

This often results from FX overrides in projectile configuration files. All projectile-related configurations are located at: <project_name>/develop/gameBase/gameData/weapons.

Each projectile can be used by different vehicle types. To trace and validate the applied physmat and FX settings, follow the steps below.

Identify the Vehicle

Determine the vehicle in use by checking the mission file being launched. For example, the vehicle might be:
```
`ussr_t64_b_1984`
```
Locate the Weapon Preset

Find the weapon preset for that vehicle in:
```
<project_name>/develop/gameBase/gameData/units/tankModels/weaponPresets
```
For the example above, the corresponding file might be:
```
ussr_t_64_b_1984_common.blk
```
Locate the Projectile Definitions

Assume you’re inspecting machine gun behavior. The process is identical for all projectile types. Common weapon configurations include:
- groundModels_weapons/7_62mm_PKT_user_machinegun.blk
- groundModels_weapons/12_7mm_NSV_user_cannon.blk
Open the relevant file to inspect projectile includes. Go to the relevant configuration files and find references to the fx directory at <project_name>/develop/gameBase/gameData/weapons/fx (this directory contains the FX settings for projectiles).

For example, in 7_62mm_PKT_user_machinegun.blk:
```
include "#/develop/gameBase/gameData/weapons/bullets/USSR/_7_62mm_shkas_b32_bullet.blk"
```
In turn, this bullet definition includes an FX configuration:
```
include "#/develop/gameBase/gameData/weapons/fx/_8_11mm_ap_hit_fx.blk"
```
Likewise, in 12_7mm_NSV_user_cannon.blk:
```
include "bullets/ussr/_12_7mm_dshk_bzt_44_APIT_bullet.blk"
include "bullets/ussr/_12_7mm_dshk_mdz_HE_bullet.blk"
include "bullets/ussr/_12_7mm_dshk_bs41_API_bullet.blk"
```
These include references like:
```
include "#/develop/gameBase/gameData/weapons/fx/_12_18mm_ap_hit_fx.blk"
```

Inspect FX Configuration Files

Open the .blk files under weapons/fx/ to review their effect definitions.

For example, in _12_18mm_he_hit_fx.blk:

groundCollisionEffect:t = "hit_12_18mm_dirt_he" // Default FX when hitting the ground.
                                                // Used if the physmat lacks a defined 'hitFxType:t'.
ricochetEffect:t = "hit_12_18mm_metal_ap"       // FX for ricochets on metal surfaces.
waterCollisionEffect:t = "hit_12_18mm_water"    // FX for impacts on water surfaces.
                                                // Also used when no specific 'hitFxType:t' is provided.

The file may also contain a collisions block for physmat-specific overrides:

collisions{
  default{                       // physmat name
    fx:t = "hit_12_18mm_dirt_he" // Overrides 'hitFxType:t' with a hardcoded FX for this projectile.
  }
  horLandMesh{
    fx:t = "hit_12_18mm_dirt_he"
  }
  ...
}

Defining Physmats in Game Resources

Physmats can be assigned to various game assets such as prefabs or ground decals by modifying their material properties. Proper assignment ensures correct behavior during interactions like vehicle movement, projectile impacts, and environmental effects.

Prefabs

To assign a physmat to a prefab, append the physmat name to the material definition using the @ symbol:

name:t = "lake@ice"

In this example, the material “lake” is associated with the ice physmat.

Ground Decals

For decals that require explicit physmat behavior, the physmat can be defined using the script parameter in the material properties:

script:t="phmat=concrete" // where "concrete" is the desired physmat type.

This assigns the concrete physmat to the decal. It is typically used for decals that represent ground types, damage marks, or effects-sensitive surfaces.

Limitations and Tooling

Physmats are not currently visible in the Asset Viewer or in the daEditor and must be verified manually:

When working with daNetGame-based projects:

If a decal is placed on surfaces with mixed digging behavior (e.g., some allow shoveling, some do not), assigning a physmat to the decal is unnecessary.
In such cases, the underlying terrain’s physmat will be used during interactions like digging.

Render Instances

Physmats can be applied to render instances using one of the following methods:

Option 1: Via Material Property

Add the physmat directly to the material definition in any .blk file that describes object properties. Common files include:

_buildings_dmg.blk
_immortals.blk
rendinst_dmg.blk

Example:

material:t = "ice"

This assigns the ice physmat to the render instance.

Option 2: Via Collision Node Script

Physmats can also be assigned through the object’s collision node by adding a script block:

script {
  phmat:t = "ice"
}

This method is often more precise and ensures consistent interaction behavior.

Spline Classes

Physmats can be assigned to spline classes in two ways:

Method 1: Via Script Parameter

Add a script parameter to the spline material definition:

script:t = "phmat=rocks~r~n"

Note

If the material already uses a script parameter, append the physmat definition to the existing string.

Method 2: Via Material Name

The more reliable method is to embed the physmat directly into the material name using the @ syntax:

matName:t = "town_pavement_asphalt_debris_a@ice"

This binds the ice physmat to the spline material.

Limitations

Physmats currently apply only to simple materials and loft objects.
Assigning physmats to materials with class_name:t = "land_mesh_combined" is not supported and will have no effect.

Export Behavior

Physmats assigned to spline classes are automatically included in the physmap during level export. This ensures correct behavior in gameplay for movement, impact effects, and interaction logic.

Land Classes

Physmats can be assigned to land classes and are included in the physmap during level export. Proper configuration is essential to ensure accurate in-game physics and interaction behavior on terrain surfaces.

Physmat Requirements

Physmats can be stored within the landmesh, but they require a detailed heightmap to function correctly. Without a valid heightmap, the physmat assignment will not take effect.

Assigning Physmats in Landclass Files

There are two main approaches for assigning physmats in landclass definitions:

Method 1: Per-Channel Assignment (Splatting Mask)

Physmats can be mapped to each color channel of the splatting mask:

physMatRed:t   = "beton"
physMatGreen:t = "beton"
physMatBlue:t  = "beton"
physMatBlack:t = "beton"

Note

If a specific color channel is not defined, the default physmat will be used in its place.

Method 2: Global Assignment (Single Physmat)

To apply a single physmat to the entire land class, use the physMat parameter at the root level of the .blk file:

className:t = "landClass"
physMat:t   = "beton"

Note

This parameter must be placed at the root. If nested inside another block, it will not function.

Preventing Blending Issues

When blending materials in the splatting mask, undefined channels may fall back to an unintended default physmat. To avoid this, always define a global physMat in the root of the landclass .blk. This ensures a consistent fallback.

Biome-Specific Physmats

In biomes, landclass physmats can be assigned globally or overridden for specific detail indices:

physMat:t = "roadSoil"   // Global physmat applied to all details by default.

physMatIndices {         // Overrides for specific detail indices.
  detail { index:i = 4;  physMat:t = "roadSand" }
  detail { index:i = 15; physMat:t = "rocks"     }
  detail { index:i = 16; physMat:t = "beton"     }
}

Testing Physmats in the Game

To verify physmat behavior in-game especially for impact effects, vehicle interaction, or terrain response, a number of debug commands are available.

War Thunder Debug Commands

`trace.debug_trace`

Casts a debug ray from the camera to the surface.
Places a marker (sphere) at the point of intersection.
Displays the name of the physmat at that point.

Note

Use this to confirm which physmat is being registered under the cursor in the game world.

`Landmesh.checkPhysmat`

Similar to trace.debug_trace, but specific to landmesh surfaces.
Casts a ray and creates a debug sphere at the intersection.
Displays the physmat name at that point.

Note

Landmesh physmats now function without a detailed heightmap, but only for visual effects and simulated interactions (e.g., decals, FX). They do not support full physics interactions.

`clipmap.physmap`

Overlays the terrain with colors corresponding to physmats.
Useful for visualizing physmat distribution across the level.

Note

This command only works when landquality:i = 0 is set in config.blk, or when the terrain quality slider is set to Low in the game settings.

The color used for each physmat is not explicitly defined. It is assumed to be controlled by the color:c = R,G,B,A parameter in the physmat configuration, but this has not been confirmed.

`app.debug`

Displays all active FX in the client.
Useful for tracing visual issues, such as incorrect FX playing on impact.

Note

If a projectile plays the wrong FX on a physmat, use this command to inspect the effect in real time. This allows you to trace the FX back to projectile configuration overrides (see the Projectiles section for details).

Commands for daNetGame-based Projects

`aim.ruler <mode>`

The aim.ruler command traces a ray from the camera to the environment and visualizes physmat data at the point of intersection.

Available modes:

aim.ruler 1: Displays the physmat name and distance from the camera.
aim.ruler 2: Adds pixel-sized visual markers for physmat representation at the hit point.
aim.ruler 3: Adds a color map overlay showing physmat distribution across various surface types, including:
- Landscapes
- Decals
- Road splines
Note

Use this command during runtime to confirm physmat mappings and identify mismatches in surface interaction behavior.

Object Destruction (Windows) by Characters

A specialized physmat named window_wood is used to enable window-breaking behavior when characters jump through or push against certain objects. This physmat is finely tuned and should not be modified directly.

Note

The window_wood physmat is configured to break only under specific physical conditions, such as a character jumping through the window at a velocity near impulseSpeed:r = 2.5. It does not trigger from light contact.

How to Enable Character-based Object Breaking

To configure destructible windows (or similar objects) for character interaction:

Assign the correct physmat

Replace the existing physmat (e.g., "wood") with:
```
phmat:t = "window_wood"
```
in the collision node or object definition.
Enable physics for the object

Ensure that physical collisions are active so the object can respond to character movement.

See also

For more information, see Static Object Collisions.
Tag the object in rendinst_dmg

Add the following to the corresponding damage instance block rendinst_dmg{}:
```
material:t = "window_wood"
```
Rebuild resources

After making changes:
- Rebuild Vromfs
- Rebuild collision models for the updated assets

Physmats

Placement and Configuration

File Structure

Physmat Parameters

Aircraft-Specific Parameters

Tank-Specific Parameters

Explosion and Impact Parameters

Explosion Patch Parameters

Alternative Explosion Material

Explosion Effects

Physical Impact Modifiers

Projectile Penetration Effects

Gunfire Decal Parameters

Decal Textures

Decal Rendering Controls

Impact Effects

Vehicle Interaction Parameters

Deprecated or Unused Parameters

Mandatory Physmat Parameters for Render Instances

Overriding Physmat Parameters in Other Configurations

Projectiles

Defining Physmats in Game Resources

Prefabs

Ground Decals

Limitations and Tooling

Render Instances

Option 1: Via Material Property

Option 2: Via Collision Node Script

Spline Classes

Method 1: Via Script Parameter

Method 2: Via Material Name

Limitations

Export Behavior

Land Classes

Physmat Requirements

Assigning Physmats in Landclass Files

Method 1: Per-Channel Assignment (Splatting Mask)

Method 2: Global Assignment (Single Physmat)

Preventing Blending Issues

Biome-Specific Physmats

Testing Physmats in the Game

War Thunder Debug Commands

trace.debug_trace

Landmesh.checkPhysmat

clipmap.physmap

app.debug

Commands for daNetGame-based Projects

aim.ruler <mode>

Object Destruction (Windows) by Characters

How to Enable Character-based Object Breaking

`trace.debug_trace`

`Landmesh.checkPhysmat`

`clipmap.physmap`

`app.debug`

`aim.ruler <mode>`