Revert "Add newly shader built-ins to docs backport" (#6154)

tutorials/shaders/shader_reference/spatial_shader.rst

@@ -135,58 +135,50 @@ is usually:
 This allows you to easily adjust the shader to a particle system using default particles material. When writing a custom particle
 shader, this value can be used as desired.
 
-+--------------------------------------+--------------------------------------------------------+
-| Built-in                             | Description                                            |
-+======================================+========================================================+
-| in vec2 **VIEWPORT_SIZE**            | Size of viewport (in pixels).                          |
-+--------------------------------------+--------------------------------------------------------+
-| inout mat4 **WORLD_MATRIX**          | Model space to world space transform.                  |
-+--------------------------------------+--------------------------------------------------------+
-| in mat4 **INV_CAMERA_MATRIX**        | World space to view space transform.                   |
-+--------------------------------------+--------------------------------------------------------+
-| inout mat4 **PROJECTION_MATRIX**     | View space to clip space transform.                    |
-+--------------------------------------+--------------------------------------------------------+
-| in mat4 **CAMERA_MATRIX**            | View space to world space transform.                   |
-+--------------------------------------+--------------------------------------------------------+
-| inout mat4 **MODELVIEW_MATRIX**      | Model space to view space transform (use if possible). |
-+--------------------------------------+--------------------------------------------------------+
-| inout mat4 **INV_PROJECTION_MATRIX** | Clip space to view space transform.                    |
-+--------------------------------------+--------------------------------------------------------+
-| in vec3 **NODE_POSITION_WORLD**      | Node position, in world space.                         |
-+--------------------------------------+--------------------------------------------------------+
-| in vec3 **NODE_POSITION_VIEW**       | Node position, in view space.                          |
-+--------------------------------------+--------------------------------------------------------+
-| in vec3 **CAMERA_POSITION_WORLD**    | Camera position, in world space.                       |
-+--------------------------------------+--------------------------------------------------------+
-| in vec3 **CAMERA_DIRECTION_WORLD**   | Camera direction, in world space.                      |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec3 **VERTEX**                | Vertex in local coordinates.                           |
-+--------------------------------------+--------------------------------------------------------+
-| out vec4 **POSITION**                | If written to, overrides final vertex position.        |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec3 **NORMAL**                | Normal in local coordinates.                           |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec3 **TANGENT**               | Tangent in local coordinates.                          |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec3 **BINORMAL**              | Binormal in local coordinates.                         |
-+--------------------------------------+--------------------------------------------------------+
-| out float **ROUGHNESS**              | Roughness for vertex lighting.                         |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec2 **UV**                    | UV main channel.                                       |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec2 **UV2**                   | UV secondary channel.                                  |
-+--------------------------------------+--------------------------------------------------------+
-| in bool **OUTPUT_IS_SRGB**           | ``true`` when calculations happen in sRGB color space  |
-|                                      | (``true`` in GLES2, ``false`` in GLES3).               |
-+--------------------------------------+--------------------------------------------------------+
-| inout vec4 **COLOR**                 | Color from vertices.                                   |
-+--------------------------------------+--------------------------------------------------------+
-| inout float **POINT_SIZE**           | Point size for point rendering.                        |
-+--------------------------------------+--------------------------------------------------------+
-| in int **INSTANCE_ID**               | Instance ID for instancing.                            |
-+--------------------------------------+--------------------------------------------------------+
-| in vec4 **INSTANCE_CUSTOM**          | Instance custom data (for particles, mostly).          |
-+--------------------------------------+--------------------------------------------------------+
++--------------------------------------+-------------------------------------------------------+
+| Built-in                             | Description                                           |
++======================================+=======================================================+
+| in vec2 **VIEWPORT_SIZE**            | Size of viewport (in pixels).                         |
++--------------------------------------+-------------------------------------------------------+
+| inout mat4 **WORLD_MATRIX**          | Model space to world space transform.                 |
++--------------------------------------+-------------------------------------------------------+
+| in mat4 **INV_CAMERA_MATRIX**        | World space to view space transform.                  |
++--------------------------------------+-------------------------------------------------------+
+| inout mat4 **PROJECTION_MATRIX**     | View space to clip space transform.                   |
++--------------------------------------+-------------------------------------------------------+
+| in mat4 **CAMERA_MATRIX**            | View space to world space transform.                  |
++--------------------------------------+-------------------------------------------------------+
+| inout mat4 **MODELVIEW_MATRIX**      | Model space to view space transform (use if possible).|
++--------------------------------------+-------------------------------------------------------+
+| inout mat4 **INV_PROJECTION_MATRIX** | Clip space to view space transform.                   |
++--------------------------------------+-------------------------------------------------------+
+| inout vec3 **VERTEX**                | Vertex in local coordinates.                          |
++--------------------------------------+-------------------------------------------------------+
+| out vec4  **POSITION**               | If written to, overrides final vertex position.       |
++--------------------------------------+-------------------------------------------------------+
+| inout vec3 **NORMAL**                | Normal in local coordinates.                          |
++--------------------------------------+-------------------------------------------------------+
+| inout vec3 **TANGENT**               | Tangent in local coordinates.                         |
++--------------------------------------+-------------------------------------------------------+
+| inout vec3 **BINORMAL**              | Binormal in local coordinates.                        |
++--------------------------------------+-------------------------------------------------------+
+| out float **ROUGHNESS**              | Roughness for vertex lighting.                        |
++--------------------------------------+-------------------------------------------------------+
+| inout vec2 **UV**                    | UV main channel.                                      |
++--------------------------------------+-------------------------------------------------------+
+| inout vec2 **UV2**                   | UV secondary channel.                                 |
++--------------------------------------+-------------------------------------------------------+
+| in bool **OUTPUT_IS_SRGB**           | ``true`` when calculations happen in sRGB color space |
+|                                      | (``true`` in GLES2, ``false`` in GLES3).              |
++--------------------------------------+-------------------------------------------------------+
+| inout vec4 **COLOR**                 | Color from vertices.                                  |
++--------------------------------------+-------------------------------------------------------+
+| inout float **POINT_SIZE**           | Point size for point rendering.                       |
++--------------------------------------+-------------------------------------------------------+
+| in int **INSTANCE_ID**               | Instance ID for instancing.                           |
++--------------------------------------+-------------------------------------------------------+
+| in vec4 **INSTANCE_CUSTOM**          | Instance custom data (for particles, mostly).         |
++--------------------------------------+-------------------------------------------------------+
 
 .. note::
 
@@ -199,6 +191,21 @@ The default use of a Godot fragment processor function is to set up the material
 and to let the built-in renderer handle the final shading. However, you are not required to use all
 these properties, and if you don't write to them, Godot will optimize away the corresponding functionality.
 
+Below are examples of common variables calculated using the built-ins:
+
+.. code-block:: glsl
+
+    vec3 model_world_space = WORLD_MATRIX[3].xyz; // Object's world space position. This is the equivalent to global_transform.origin in GDScript.
+    mat3 model_transform_basis = mat3(WORLD_MATRIX); // Object's world space transform basis. This is the equivalent to global_transform.basis in GDScript.
+    vec3 camera_world_space = CAMERA_MATRIX[3].xyz; // Camera's world space position. This is the equivalent to camera.global_transform.origin in GDScript.
+    vec3 camera_eye_world_space = INV_CAMERA_MATRIX[3].xyz; // Camera eye vector in world space direction of the camera.
+    vec3 camera_to_object_world_space = normalize(WORLD_MATRIX[3].xyz - CAMERA_MATRIX[3].xyz); // Camera's direction to the object in world space.
+
+.. note::
+
+    A commonly used alternative to ``WORLD_MATRIX[3].xyz`` is to use ``vec3 origin = (WORLD_MATRIX * vec4(0,0,0,1)).xyz``. It is more efficient to use ``WORLD_MATRIX[3].xyz`` as it avoids the matrix multiplication. 
+
+
 +-----------------------------------+--------------------------------------------------------------------------------------------------+
 | Built-in                          | Description                                                                                      |
 +===================================+==================================================================================================+
@@ -217,14 +224,6 @@ these properties, and if you don't write to them, Godot will optimize away the c
 +-----------------------------------+--------------------------------------------------------------------------------------------------+
 | in mat4 **INV_PROJECTION_MATRIX** | Clip space to view space transform.                                                              |
 +-----------------------------------+--------------------------------------------------------------------------------------------------+
-| in vec3 **NODE_POSITION_WORLD**   | Node world space position.                                                                       |
-+-----------------------------------+--------------------------------------------------------------------------------------------------+
-| in vec3 **NODE_POSITION_VIEW**    | Node view space position.                                                                        |
-+-----------------------------------+--------------------------------------------------------------------------------------------------+
-| in vec3 **CAMERA_POSITION_WORLD** | Camera world space position.                                                                     |
-+-----------------------------------+--------------------------------------------------------------------------------------------------+
-| in vec3 **CAMERA_DIRECTION_WORLD**| Camera world space direction.                                                                    |
-+-----------------------------------+--------------------------------------------------------------------------------------------------+
 | in vec3 **VERTEX**                | Vertex that comes from vertex function (default, in view space).                                 |
 +-----------------------------------+--------------------------------------------------------------------------------------------------+
 | in vec3 **VIEW**                  | Vector from camera to fragment position (in view space).                                         |