VRayHDRI map

General

Tiled OpenEXR files

Parameters

Tiled texture options

Coordinates

Notes

General

The VRayHDRI map can be used to load high dynamic range images (HDRI) and map them onto the environment. Supports most of the standard HDRI-environment mapping methods. Since V-Ray 2.0, this texture can also be used to load other file formats.

Tiled OpenEXR files

Since V-Ray 2.0, this texture can also be used to load efficiently tiled OpenEXR files. Tiled OpenEXR files allow only portions of the textures to be loaded at various resolutions. This allows V-Ray to only load those parts of the textures that are needed for the rendering.

 

You can convert many common image file formats to tiled OpenEXR files using the img2tiledexr tools.

Parameters

Bitmap - the file name from which the bitmap is loaded. Currently supported formats are HDR, EXR, PNG, BMP, TGA, SGI, JPG, PIC, TIF, PSD, VRIMG. Image file lists in the form of IFL files are also supported.

 

Browse - click this button to browse for an HDR image.

 

Mapping

 

These parameters determine how the VRayHDRI texture is mapped.

 

Mapping type - the following mapping types are supported:

• Angular - environment mapping in angular mode;
• Cubic - environment mapping in cubic mode;
• Spherical - environment mapping in spherical mode;
• Mirrored ball - environment mapping in mirror ball mode;
• 3ds Max standard - the mapping type is determined by the Coordinates section.

 

Horiz. rotation - allows rotation of the environment map left and right. Ignored when the Mapping type is 3ds Max standard.

 

Flip horizontally - flips the environment horizontally. Ignored when the Mapping type is 3ds Max standard.

 

Vert. rotation - allows rotation of the environment map up and down. Ignored when the Mapping type is 3ds Max standard.

 

Flip vertically - flips the environment vertically. Ignored when the Mapping type is 3ds Max standard.

 

Processing

 

Overall multiplier - a control for the overall brightness of the image. This multiplier affects both rendering and the material editor.

 

Render multiplier - controls the brightness of the HDRI image only when rendering; it has no effect on the display of the image in the material editor.

 

Gamma - a gamma-correction value for the image. For example, if the bitmap was saved to disk with a 2.2 gamma correction, you need to enter 0.4545 to remove that correction for the rendering.

 

Interpolation - determines how the image is interpolated from the pixel values. See the Examples for a demonstration of this effect. Possible values are:

 

• Bilinear - the image values are interpolated from four pixels in the bitmap. This is the fastest interpolation method, but the result is not continuous (non-smooth) and may produce artifacts when the map is used for displacement or bump mapping.
  
  
• Bicubic - the image values are interpolated from sixteen pixels in the bitmap. This is the slowest method, but the results are smooth without too much blur;
  
  
• Biquadratic - the image values are interpolated from nine pixels in the bitmap. This method is faster than the Bicubic interpolation, but may smooth the image too much.
  
  
• Default - the interpolation type is chosen automatically depending on the bitmap format to match the behavior of the standard 3ds Max Bitmap texture. For HDR and EXR images, the interpolation is Bilinear, and for all other formats - Bicubic.

 

Tiled texture options

These options are shared between all instances of the VRayHDRI texture; changing them in one texture affects all other textures.

 

Tiled texture cache size - the size of the cache for tiled OpenEXR files, in megabytes. When the texture cache is full, part of the tiles will be flushed to make space for loading new tiles as needed.

 

Clear cache on render end - if enabled, the texture cache is flushed at the end of each frame. This may save some RAM, but will cause the texture tiles to be reloaded on each frame.

Coordinates

These parameters are used when the Mapping type is set to 3ds Max standard. They are the regular 3ds Max mapping parameters as found in the standard 3ds Max Bitmap texture.

Notes

• Since V-Ray 2.0, VRayHDRI will load the texture the first time it is needed during the actual rendering, rather than at the start of a frame. Textures that are not needed (for example, because their materials are not needed for the particular camera angle) will not be loaded at all.
  
  
• When using tiled OpenEXR textures, it is recommended to turn on the Filter maps for GI option in the Global Switches section; otherwise V-Ray will be forced to almost always load the most detailed version of the texture.