cell nucleus 3d model

Create a highly detailed educational 3D model of a biological cell nucleus, designed as a clean standalone scientific visualization. The model should feature a semi-open spherical nuclear envelope with realistic membrane thickness and small nuclear pores distributed across the surface. Inside the nucleus, include a prominent nucleolus as a smooth spherical structure surrounded by soft nucleoplasm filling the interior. Add subtle chromatin strands and clusters embedded throughout the nucleoplasm. Around the outer lower region of the nucleus, model interconnected folds of endoplasmic reticulum with organic membrane-like structures. Use realistic biological forms, smooth surfaces, high-quality PBR materials, subsurface scattering, soft translucency, and accurate scientific proportions. The nucleus should be partially cut away to reveal internal structures clearly. Floating isolated object on a transparent or plain background. Medical illustration quality, museum exhibit quality