This paper presents a technique for rendering images of volumes containing mixtures of materials. The method allows both the interior of a material and the boundary between materials to be colored. Image projection is achieved by simulating the absorption of light along the ray path to the eye. The algorithms are designed to avoid artifacts caused by aliasing and quantization and can be efficiently implemented on an image computer. The technique is applicable to various applications, including medical imaging, computed tomography (CT), magnetic resonance imaging (MRI), non-destructive evaluation (NDE), and scientific visualization. The method directly operates on volumetric data, assuming the data is sampled above the Nyquist frequency or low-pass filtered to remove high frequencies that cause aliasing. This ensures the original continuous representation of the volume can be reconstructed from the samples. The algorithm preserves the continuity of the data throughout each stage, avoiding thresholding and other highly non-linear operations that can introduce artifacts. The algorithm involves several steps: converting the input data volume to material percentage volumes, calculating composite volumes based on material properties, detecting boundaries between materials using gradients, and shading the volume to represent light emission and surface scattering. The shaded volume is then transformed and resampled to lie in the viewing coordinate system, and projected onto the image plane to form the final image. The technique also includes matting operations to remove sections or reduce the presence of certain materials, and surface extraction to determine surface normals and strengths. The lighting model accounts for both volumetric emission and surface reflection, with the reflected surface color depending on the surface normal, strength, and light source properties. The algorithm is efficient and can be adapted for real-time rendering, as only the stages that change from frame to frame need to be recomputed. The method is particularly effective for visualizing complex volumetric data, as it models both volumetric and surface properties, preserving the continuity of the data and avoiding artifacts. The technique has been applied to various applications, including medical imaging, biological studies, and physical science simulations, demonstrating its versatility and effectiveness in visualizing volumetric data.This paper presents a technique for rendering images of volumes containing mixtures of materials. The method allows both the interior of a material and the boundary between materials to be colored. Image projection is achieved by simulating the absorption of light along the ray path to the eye. The algorithms are designed to avoid artifacts caused by aliasing and quantization and can be efficiently implemented on an image computer. The technique is applicable to various applications, including medical imaging, computed tomography (CT), magnetic resonance imaging (MRI), non-destructive evaluation (NDE), and scientific visualization. The method directly operates on volumetric data, assuming the data is sampled above the Nyquist frequency or low-pass filtered to remove high frequencies that cause aliasing. This ensures the original continuous representation of the volume can be reconstructed from the samples. The algorithm preserves the continuity of the data throughout each stage, avoiding thresholding and other highly non-linear operations that can introduce artifacts. The algorithm involves several steps: converting the input data volume to material percentage volumes, calculating composite volumes based on material properties, detecting boundaries between materials using gradients, and shading the volume to represent light emission and surface scattering. The shaded volume is then transformed and resampled to lie in the viewing coordinate system, and projected onto the image plane to form the final image. The technique also includes matting operations to remove sections or reduce the presence of certain materials, and surface extraction to determine surface normals and strengths. The lighting model accounts for both volumetric emission and surface reflection, with the reflected surface color depending on the surface normal, strength, and light source properties. The algorithm is efficient and can be adapted for real-time rendering, as only the stages that change from frame to frame need to be recomputed. The method is particularly effective for visualizing complex volumetric data, as it models both volumetric and surface properties, preserving the continuity of the data and avoiding artifacts. The technique has been applied to various applications, including medical imaging, biological studies, and physical science simulations, demonstrating its versatility and effectiveness in visualizing volumetric data.