# NNS_G3D_SBC_ENVMAP

## Command Format

Offset (bytes) | Description
--- | ---
0 | `NNS_G3D_SBC_ENVMAP | NNS_G3D_SBCFLG_000`
1 | The material ID.
2 | Flag for expansion (Currently always set to 0).

## Description

When the texture coordinate conversion mode designated by the NITRO intermediate file `.imd` format `<material>::tex_gen_mode` is `nrm`, the `NNS_G3D_SBC_ENVMAP` command is configured immediately after the `NNS_G3D_SBC_MAT` command. This command calculates and configures the texture matrix for the environment map. Depending on the callback function, each of the texture matrix calculation operations can be replaced.

Timing for Calling a Callback Function | Usage
--- | ---
`NNS_G3D_SBC_CALLBACK_TIMING_A` | Allows for the customization of the calculation that maps the normal to the texture coordinates.
`NNS_G3D_SBC_CALLBACK_TIMING_B` | Allows for the customization of the calculation that rotates and scales the normal in the view coordinate system.
`NNS_G3D_SBC_CALLBACK_TIMING_C` | Allows for the customization of the calculation used to convert the input normal to a view coordinate system.

## See Also

## Revision History

2005/01/17 Initial version.

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