VRayBitmap

Bitmap – Specifies 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 image file.

Reload – Forces V-Ray to reload the texture from the hard drive.

View image – Shows a preview of the loaded map.

Locate – Opens the folder in which the texture file is located in a new Windows Explorer window.

These parameters determine how the VRayBitmap texture is mapped.

Mapping type – The following mapping types are supported:

Angular – Uses a map that looks as if taken with a fisheye lens, i.e. the projection assumes that the camera is in the center of a sphere. Тhese types of maps are efficient as most of the stored pixels are used except for those at the corners of the map. Note that there is significant distortion.
Cubic – Uses a 3x4 Cube map (Vertical cross). Cubic type is mostly used to create a seamless environment around the camera by being wrapped on a cube. The method captures a complete 360° of vision. Some areas of the bitmap are not included in the final projection, making the map less efficient as not all stored pixels are used.
Spherical – Uses a 2x1 stretched 2D bitmap representation of a sphere. Spherical type is mostly used to create a seamless environment around the camera by being wrapped on a sphere. The method captures a complete 360° of vision. The maps are very efficient because all the stored pixels are used.

Mirrored ball – Uses a 1x1 bitmap of a warped hemisphere. The method captures 180° horizontally and 180° vertically, not making it seamless.
3ds Max standard – The mapping type is determined by the Coordinates section.

Horiz. rotation – Allows left and right rotation of the environment map. 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 up and down rotation of the environment map. Ignored when the Mapping type is 3ds Max standard.

Flip vertically – Flips the environment vertically. Ignored when the Mapping type is 3ds Max standard.

Mapping source – Provides control over the UV mapping of the VRayBitmap texture from another map. Use either another VRayBitmap map (see the Coordinates example) or any texture with Coordinates rollout (e.g. Checker) to feed all its Coordinates parameters values. Use VRayTriplanarTex and VRayUVWRandomizer maps to benefit from their enhanced mapping options.

Multiple VRayBitmap maps can use the same map as Mapping Source and this way simultaneously control their tiling, offset, rotation and other mapping features.

See the example here

Click on the image to enlarge it.

These controls allow you to "flatten" the bottom part of an environment map onto a virtual plane. This is useful for rendering CG objects when you only have an environment map.

Note: The ground projection works for environment maps and for textures assigned to a Dome light.

On – Enables or disables the ground projection.

Position – The X, Y and Z coordinates of a point in 3D space where the center of the environment map is projected.

Radius – Specifies a projection radius. Can be used to control the scale of the projection.

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 loaded image only when rendering; it has no effect on the display of the image in the material editor.

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

Bilinear – 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 – 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 – 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  – 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.

Filter mult. – Additional multiplier which controls filter blurring, especially useful with the mapping source feature. The higher the value, the more blurred the texture renders and the less render time it takes, and vice versa. A value of 0.01 means no filtering, but leads to increased render times. If a Bitmap is connected to the VRayBitmap as a mapping source, the Filter multiplier option serves as a multiplier for the Blur parameter of the Bitmap. For example, if the Bitmap Blur parameter is set to 10, and the VRayBitmap Filter multiplier is set to 0.1, the texture blur amount is effectively, 1. 

Filtering – Specifies the V-Ray internal texture filtering method. See the Filtering examples below. Possible values are:

Isotropic – Pyramidal MIP map filtering is used to compute the texture color. Can be blurry for textures seen at grazing angles. 
Elliptical – High quality anisotropic MIP map texture filtering that reduces blurring and aliasing artifacts. Can be slower compared to the Isotropic filtering. 
Sharp Isotropic – Sharper and more accurate version of the isotropic filtering. Produces results that are closer to the results with disabled filtering but with less AA samples required.

The controls in this group let you crop the texture or reduce its size for custom placement. Cropping a texture means reducing it to a smaller rectangular area than it originally had. Cropping doesn't change the scale of the texture.

Placing a texture lets you scale the map and place it anywhere within its tile. Placing can change the texture's scale, but shows the entire texture. The four values that specify the placement and size of the cropping or placement region are all animatable. Cropping and placement settings affect the texture only as it's used for this map and any instances of the map. They have no effect on the texture file itself.

On – Turn on to use the cropping or placement settings.

Crop – Enables cropping.

Place – Enables placing.

Preview – Opens a preview window with a red rectangle for the crop/placement.

U/V – Adjusts the texture location - specifies the location of the top left corner of the image.

Width/Height – Adjusts the width and height of the texture or crop area.

These controls allow the user to specify how the color and alpha of the resulting texture are derived.

RGB output – Specifies the source for the color of the texture:

RGB color – The normal texture color;
Alpha as gray – The color of the texture is the alpha channel converted to a grayscale color;
Intensity as gray – The texture converted to grayscale colors based on the intensity of the colors (red+green+blue)/3

Alpha source – Determines how the texture alpha is computed:

Image alpha – From the alpha channel of the bitmap image, if present (and 1.0 if the image has no alpha channel);
Intensity – The alpha is taken from the intensity of the bitmap image colors (red+green+blue)/3;
None (opaque) – The alpha channel of the bitmap image is ignored and the VRayBitmap texture always returns 1.0 for alpha.

Mono output – Determines the value of the texture when used as a floating-point texture (e.g. for glossiness values in materials, amount values, opacity values, etc.):

RGB intensity – The mono output is taken from the bitmap color intensity (red+green+blue)/3;
Alpha – The mono output is taken from the bitmap alpha.

Type – Specifies the transfer function for the loaded image file.

None – No correction is applied;
Inverse gamma – The transfer function is controlled through the Inverse Gamma parameter.
sRGB  – The loaded image is considered in sRGB transfer function;
From 3ds Max – The gamma is controlled from 3ds Max gamma settings (Customize -> Preferences -> Gamma and LUT).
Auto – Automatically determines the color transfer function. If a bitmap file name contains the string "_srgb" the transfer function is sRGB. If a bitmap file name contains the strings "_lin_srgb" or "raw", no correction is applied. For bitmap files with 8 bits per color component, 3 or 4 color components (like png, jpg, and other) and no suffix, the transfer function is sRGB. In all other cases, no correction is applied.

Inverse 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.

Use full resolution for viewport – When enabled, ignores the requested viewport resolution and uses the bitmap resolution instead. This allows high-quality previews for specific maps regardless of the Max viewport settings. Note that 3ds Max does not support resolutions larger than 16384x16384.

These options allow you to specify which UV tile will be used to texture the material in the material preview when either UDIM or UVTILE texturing is used.

These options allow you to control animated textures. Currently it works only with IFL sequences.

Start Frame – Specifies the beginning of the texture animation. The frame number specified here will be played at the first frame of the scene animation.

Playback Rate – Controls the animation speed of the texture as fraction of the actual animation speed. A value of 1 means that the texture animation will run at regular speed. A value of 2 means that the texture animation will run twice as fast as the scene animation.

End Condition – Allows you to control what happens when the last frame of the animated texture is reached. The available options are:

Loop – The animation will start again from the frame specified in the Start Frame option;
Ping-pong – The animation will be played backwards until it reaches the frame specified in the Start Frame option and then play forward again;
Hold – The animation will stop at the last frame and it will be displayed until the end of the scene animation.

RGB primaries – Allows you to manually override the RGB primaries of the VRayBitmap.

Default – When Auto RGB primaries for VRayBitmap textures option in Render Setup > Color Management tab is enabled, the color space is deduced by the file's name. When it is disabled, no transformation is applied to R|G|B colors;
sRGB primaries – The loaded image is considered in sRGB color space;
ACEScg primaries – The loaded image is considered in ACEScg color space;
Raw – No transformation is applied to R|G|B colors. This option is suitable for normal maps.

The Coordinates 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. 

V-Ray includes a MaxScript tool for converting standard 3ds Max Bitmap textures to VRayBitmap textures, with the option to automatically convert the texture files to tiled OpenEXR files. The tool can be invoked by right-clicking in any viewport and selecting V-Ray Bitmap to VRayBitmap converter. For more details, please see the V-Ray Bitmap to VRayBitmap Converter Tool page.