c4d.BaseShader¶

class c4d.BaseShader¶: Represents a shader in the shader tree of a channel.

Methods Signatures

BaseShader.__init__()

Initialize a new BaseShader in memory.

`BaseShader.Sample()`	Calls `ShaderData.Output()` for the corresponding shader plugin.
`BaseShader.SampleBump()`	Calculates the bump mapping for a shader (and its children) with the same algorithm as Cinema 4D does.
`BaseShader.GetBitmap()`	Returns the bitmap of shaders of type Xbitmap, otherwise None.
`BaseShader.GetRenderInfo()`	Calls ShaderData.GetRenderInfo() for the corresponding shader plugin.
`BaseShader.InitRender()`	Calls `ShaderData.InitRender()` for the corresponding shader plugin.
`BaseShader.FreeRender()`	Frees all resources used by this shader, allocated by calling `InitRender()`.
`BaseShader.IsColorManagementOff()`	It checks if color management is disabled for shaders within bump, alpha, displacement or normal channels when linear workflow is enabled.
`BaseShader.Compare()`	Checks if this shader is similar to dst.

Inheritance

Parent Class:

c4d.BaseList2D

Child Class:

c4d.LayerShader

Methods Documentation

BaseShader.__init__(self, type)¶

Initialize a new BaseShader in memory.

Parameters: type (int) – The shader type : Shader Types.

BaseShader.Sample(self, cd)¶

Calls ShaderData.Output() for the corresponding shader plugin.

The channel color for the point cd.p is calculated.

Note

This has to be done within a pair of InitRender() / FreeRender() calls.

Parameters: cd (c4d.modules.render.ChannelData) – The channel data to use.
Return type: c4d.Vector
Returns: The calculated color.

BaseShader.SampleBump(self, cd, bumpflags)¶

Calculates the bump mapping for a shader (and its children) with the same algorithm as Cinema 4D does.

The function returns the delta vector that is added to the normal.
The resulting normal is calculated by:

n_dst =  not(n_src + SampleBump(SAMPLEBUMP_NONE))

where n_src is the original normal and n_dst is the bumped normal.

Note

This has to be done within a pair of InitRender() / FreeRender() calls.

Also the BaseVolumeData.ddu and BaseVolumeData.ddv vectors have to be initialized.

Parameters

cd (c4d.modules.render.ChannelData) – The channel data to use.
bumpflags (int) –
Flags:

SAMPLEBUMP_NONE

None.

SAMPLEBUMP_MIPFALLOFF

Additional bump change over distance is considered.

Return type

c4d.Vector

Returns

The delta normal.

BaseShader.GetBitmap(self)¶

Returns the bitmap of shaders of type Xbitmap, otherwise None.

Note

This has to be done within a pair of InitRender() / FreeRender() calls.

Here is an example.

# Get the first material in the document.
material = doc.GetFirstMaterial()
if material is None:
    raise RuntimeError("Could not find material.")

# Retrieve the shader linked in the color channel.
shader = material[c4d.MATERIAL_COLOR_SHADER]
if shader is None:
    raise RuntimeError("Material has no shader.")

# Initialize an InitRenderStruct.
irs = render.InitRenderStruct()
if irs and shader.InitRender(irs) == c4d.INITRENDERRESULT_OK:
    # Get the bitmap.
    bitmap = shader.GetBitmap()
    # Free the renderer so that that its memory can be freed.
    shader.FreeRender()
    # Show the bitmap in the Picture Viewer.
    if bitmap is not None:
        bitmaps.ShowBitmap(bitmap)

Return type

Optional[c4d.bitmaps.BaseBitmap]

Returns

The bitmap.

Note

The returned bitmap must be accessed as read-only.

BaseShader.GetRenderInfo(self)¶

Calls ShaderData.GetRenderInfo() for the corresponding shader plugin.

This retrieves information about what the plugin requires from the raytracer and what it will return.

Return type

int

Returns

The return values are:

SHADERINFO_NONE	None.
SHADERINFO_TRANSFORM	Channel needs back-transformed data. (Required for `BaseVolumeData.back_p`.)
SHADERINFO_BUMP_SUPPORT	Channel shader supports bump. This is strongly recommended for all shaders except simple 2D (UV) samplers.
SHADERINFO_ALPHA_SUPPORT	Channel shader supports alpha output.
SHADERINFO_REFLECTIONS	Channel shader computes reflections.
SHADERINFO_DUDVREQUIRED	Channel shader needs du/dv bump mapping data. See `BaseVolumeData.ddu` and `BaseVolumeData.ddv`.
SHADERINFO_DYNAMICSUBSHADERS	Channel shader has a dynamic list of sub-shaders in its description.

BaseShader.InitRender(self, is_)¶

Calls ShaderData.InitRender() for the corresponding shader plugin.

You have to do this before you can use the Sample(), SampleBump() or GetBitmap() functions.

Note

Remember to call FreeRender() afterwards.

You aren’t allowed to call InitRender() multiple times without calling FreeRender() in between, even from multiple threads!

Parameters

is (c4d.modules.render.InitRenderStruct) – Information about the upcoming rendering.

Return type

int

Returns

Result of the initialisation:

INITRENDERRESULT_OK	Everything is OK, there was no error.
INITRENDERRESULT_OUTOFMEMORY	Not enough memory.
INITRENDERRESULT_ASSETMISSING	Assets (textures etc.) are missing.
INITRENDERRESULT_UNKNOWNERROR	Unknown error.
INITRENDERRESULT_USERBREAK	Changed in version R17.032: Was INITRENDERRESULT_THREADEDLOCK. Thread has been canceled.

BaseShader.FreeRender(self)¶: Frees all resources used by this shader, allocated by calling InitRender().

BaseShader.IsColorManagementOff(self, doc)¶

It checks if color management is disabled for shaders within bump, alpha, displacement or normal channels when linear workflow is enabled.

Parameters: doc (c4d.documents.BaseDocument) – The document containing the shader to check if linear workflow is disabled in it.
Return type: bool
Returns: True if color managment is disabled, otherwise False.

BaseShader.Compare(self, dst)¶

Checks if this shader is similar to dst.

Parameters: dst (c4d.BaseShader) – The shader to compare to.
Return type: bool
Returns: True if the plugin shaders are the same, otherwise False.

SAMPLEBUMP_NONE	None.
SAMPLEBUMP_MIPFALLOFF	Additional bump change over distance is considered.