The paper presents a technique for rendering images of volumes containing mixtures of materials, focusing on both the interior and boundaries between materials. The shading model allows for the simulation of light absorption along ray paths to the viewer's eye, avoiding artifacts caused by aliasing and quantization. The algorithms are designed to be efficiently implemented on image computers. The technique is applicable to various fields, including medical imaging, computed tomography (CT), magnetic resonance imaging (MRI), non-destructive evaluation (NDE), scientific visualization, and image processing. The paper discusses the challenges of visualizing volumes and the limitations of traditional surface rendering techniques, which often fail to capture subtle variations in density or opacity. The proposed method directly works with the volume data, ensuring smooth and realistic results. The process involves converting input data into material percentage volumes, detecting boundaries using a three-dimensional gradient, and computing shaded color volumes that account for both volume emission and surface scattering. The final image is formed by projecting the shaded volume onto the image plane, considering light transmission through each voxel. The paper also covers the use of matte volumes for removing or altering certain regions and the lighting model for simulating light interactions within the volume. Examples of rendered images from medical, biological, and scientific applications are provided to demonstrate the effectiveness of the technique.The paper presents a technique for rendering images of volumes containing mixtures of materials, focusing on both the interior and boundaries between materials. The shading model allows for the simulation of light absorption along ray paths to the viewer's eye, avoiding artifacts caused by aliasing and quantization. The algorithms are designed to be efficiently implemented on image computers. The technique is applicable to various fields, including medical imaging, computed tomography (CT), magnetic resonance imaging (MRI), non-destructive evaluation (NDE), scientific visualization, and image processing. The paper discusses the challenges of visualizing volumes and the limitations of traditional surface rendering techniques, which often fail to capture subtle variations in density or opacity. The proposed method directly works with the volume data, ensuring smooth and realistic results. The process involves converting input data into material percentage volumes, detecting boundaries using a three-dimensional gradient, and computing shaded color volumes that account for both volume emission and surface scattering. The final image is formed by projecting the shaded volume onto the image plane, considering light transmission through each voxel. The paper also covers the use of matte volumes for removing or altering certain regions and the lighting model for simulating light interactions within the volume. Examples of rendered images from medical, biological, and scientific applications are provided to demonstrate the effectiveness of the technique.