Image

The image node is a color shader that performs texture mapping using a specified image file. You can control the position, size, and rotation of this frame on the surface. You can control how the texture is tiled within the frame using the scale UV, flip, wrap, and swap attributes.

 

Filename

The image filename. UDIM token functionality is supported. For efficiency reasons, UDIM substitution is not supported if image.filename is linked. The full path name must be used.

Multiply

Multiplies the image by a constant.

Offset

Uniformly darkens or lightens the texture.

Color Space

The colorspace to use for linearization when automatically generating .tx textures. You can specify which color space the texture is assumed to be in. Built-in values are linearsRGB and Rec709. The default value 'auto' will use sRGB for integer (8 or 16 bit) formats and linear otherwise.

Filter

Texel interpolation method used to filter the rendered image file. The options are closest, bilinear, bicubic, smart_bicubicand the default is smart_bicubic. Cubic is slower but smoother, closest is faster but looks blocky when magnified.

Mipmap Bias

Mip-Mapping Bias offsets the computed Mip-Map level from which the image is sampled. A negative value will force a larger Mip-Map level (clearer image); a positive value will force a smaller Mip-Map level (blurrier image).

An example of mipmap image storage.

The first image on the left is shown with filtered copies reduced in size.

Single Channel

Read and outputs only the first channel of the image (which is usually R). You can force other channels by defining Start Channel.

Missing Texture Color

Returns the chosen color when the UVs are out of the [0,1] range. 

Ignore Missing Texture Errors

If the file corresponding to a UDIM tile is not found then by default, the render will give an error and not progress. If this option is checked, then it will not give an error and display the 'missing texture color' instead. 

Auto-Generate TX Textures

Automatically generates tiled and mipmapped TX textures. The TX texture will be linearized according to the colorspace parameter. There is also a button next to the filename to force the regeneration of TX files, and switching colorspace will regenerate the .tx textures if necessary and update the IPR.

 

UV

Custom UVs

If uv coords are linked to a shader, the evaluation of the parameter will be used as the UV coordinates to sample the image, instead of the polymesh ones. Texture derivatives are not computed in this scenario, destroying texture mapping performance, especially in scenes with many, high-resolution textures.

UV Set

A string with the name of the UV set to use to sample the image. By default, when the uvset parameter is empty, the primary UV set in the polymesh will be used. Example: If you have created a UV set in a polymesh node called "UVset2", then you can use it by setting the uvset parameter to "UVset2".

Offsets the image in the U direction. This offset takes place before scaling, flipping, or swapping of the S and T coordinates. 

Offsets the image in the V direction. This offset takes place before scaling, flipping, or swapping of the S and T coordinates. 


Scale U, Scale V

Scales the image.

Wrap U, Wrap V

Controls how a texture repeats in the V direction on a large surface. Choose between Periodic, Black, Clamp, Mirror and File. The default wrap mode is Periodic. The default wrap mode for tiles (UDIM, etc) is Mirror. The Missing wrap mode works similarly to Black, however, lookups to the image shader that are outside of the texture will use the missing_texture_color.

File wrap mode uses the wrap setting encoded in the file itself (only applies to OpenEXR files). This is useful to preserve information about how a texture should wrap without manual correction afterward. In certain cases, 'file' mode can prevent edges. For that, to work you will need to make the correct choice when you generate mipmaps with 'maketx'. 


The example below shows an OpenEXR file used as a lat-long skydome that has the file wrap modes set to 'periodic, clamp'. Generating mip maps with this mode prevents artifacts at the sphere poles. When you leave wrap modes with their default values (periodic, periodic), you can see a dot at the top of the sphere. However, if you set wrap modes to 'file' (and use a file that has the correct wrap modes in the metadata), the dot will no longer be visible.

 

Swap U & V

Swaps the axes.

Flip U

Flip (mirror) the image in the horizontal direction.

Flip V

Flip (mirror) the image in the vertical direction.

 

 

 

Pepe model by Daniel M. Lara (Pepeland)

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