## 4 Discussion  
This iteration of the web application serves as a proof of concept for a dedicated web platform designed to manage and disseminate 3D digitized and multimodal imaging data for a wide range of cultural heritage assets, including buildings and museum collection items. It revolves around the concept of an H-BIM and digital twins for historical structures and cultural artefacts, with a particular emphasis on the utilization and enhancement of 3D scanned data. As elaborated in this paper, the current version has limited features, but it effectively showcases the capabilities of the underlying technologies. Section 2.5 provides a brief overview of forthcoming updates. While the concept is based on a minimal but versatile web application, it relies on a well-planned data collection strategy. All of the subject areas of interest must be defined beforehand so that 3D digitization and multimodal imaging data can be correctly recorded and referenced. Figure 12 depicts the flow of data from the moment of recording to the registration in the web application database and server disk. This workflow stems from the realism requirement of the concept. Data should be presented in the online interactive environment and retain as much of the geometrical details of the original 3D scan. The proposed steps successfully lead to such an achievement, the main condition being the quality of the original scan. The free Blender software plays a central role in this workflow. Here, the first action within Blender is to import, duplicate (for baking purposes), and align all of the subject's digitized sources into a single object. Then, the object is split into the parts of interest, and new UV coordinate maps are generated for each of the resulting sections. After this step, the colour texture coordinates will no longer match with the 3D surface, so it needs to be baked later from the duplicate mesh. The final object is repositioned in the scene, losing its initial coordinates. For this reason, the workflow requires, in this initial stage, both low-poly and high-poly meshes so that they keep the same 3D coordinates during alignment and repositioning. When exported to another software--Substance 3D Painter--to generate the normal maps, the low-poly and high-poly meshes must have the same position for a correct geometry mapping. Normal map baking will generate a texture for each separate part of the object and will export them as separate files. Back in Blender, the normal maps can be imported to check the details directly on the low-poly mesh. At this point, the colour texture for each part can be baked as well and saved to the disk. In this case, there was another photogrammetric 3D model resulting from the aerial thermal images. The purpose of this model was just to use its texture to create a set of thermal textures for each part of the main model. The thermal mesh is imported into the same scene in Blender and aligned to the position of the main model, and then, for each part, a new texture is baked and saved to the disk. For the other imaging systems, the simplest method to create textures is to overlap them with the colour texture of the designated part in any image-editing software. In a similar manner, any other type of information that can be mapped on a surface can be included: spectral data, drawings, old photographs, etc. As an observation, photogrammetry-based data were much easier to map on 3D textures. The web application database stores the paths to the 3D model and its files, as well as other important information, like metadata and paradata. The presented form is not suitable for complex-scale projects, only for simple case studies like the one described in Section 3, where only the conservation state assessment of the external walls was needed. As this project is still in progress, a future iteration will consider beneficiary and public feedback along with the proposed development roadmap.