c4d.plugins.ShaderData¶

class c4d.plugins.ShaderData¶

A data class for creating shader (channel shader) plugins.
Use RegisterShaderPlugin() to register the plugin.
A registered shader will appear in the popup menu of the channels in the Materials Manager in Cinema 4D.

Here are some general comments on the shader API:

Coordinate Systems: if there is no further note all elements like points, normals etc. then they are always given in global coordinates.

Angle Systems: all angle values are always given in radians. Use Deg (angle) for conversion if needed.

Vectors: all normals and ray vectors must be normalized. Also, all normals and ray vectors you receive from Cinema 4D are normalized.

See also

Py-Fresnel plugin example.

Methods Signatures

`ShaderData.InitRender(self, sh, irs)`	Override - Pre-calculate any data for rendering.
`ShaderData.FreeRender(self, sh)`	Override - Free any resources used for the precalculated data from `InitRender()`.
`ShaderData.Output(self, sh, cd)`	Override - Called for each point of the visible surface of a shaded object.
`ShaderData.SetExceptionColor(self, col)`	Set the exception color.

Inheritance

Parent Class:

c4d.plugins.NodeData

Methods Documentation

ShaderData.InitRender(self, sh, irs)¶

Override - Pre-calculate any data for rendering.

Parameters

sh (c4d.BaseShader) – The shader node connected with this instance.
irs (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.

ShaderData.FreeRender(self, sh)¶

Override - Free any resources used for the precalculated data from InitRender().

Parameters: sh (c4d.BaseShader) – The shader node connected with this instance.

ShaderData.Output(self, sh, cd)¶

Override - Called for each point of the visible surface of a shaded object.

Here you should calculate and return the channel color for the point cd.p.

Important:

No OS calls are allowed during this function.

Doing so could cause a crash, since it can be called in a multi-processor context.

Parameters

sh (c4d.BaseShader) – The shader node connected with this instance.
cd (c4d.modules.render.ChannelData) – Channel data to use and/or modify.

Return type

c4d.Vector

Returns

The calculated color.

ShaderData.SetExceptionColor(self, col)¶

Set the exception color.

Parameters: col (c4d.Vector) – The exception color.