Urban spaces are defined by degrees of axial and convex extension. Space Syntax research has predominantly emphasized axial lines and maps and considered convexity through isovists and visibility graphs. Axiality emphasizes movement or flow and creates axial maps as two-dimensional networks. Convexity of urban space is aural and shaped by vision and sound in three dimensions. It is represented by convex maps of stretchable polygons (described furthermore by an adjacency scene graph within the polygons) and remain fuzzy conceptualizations because of their property as three-dimensional objects. Kevin Lynch's morphology of imageability and Michael Southworth’s soundscapes can be used to create diagrammatic representations of convex spaces as townscape representations. This paper explores the convergence of Space Syntax and imageability, soundscape and townscape theories for analysing three dimensional urban spaces in two dimensional representations. The ‘urban envelope’ creates an assemblage of building façade and street sections as fronts and empty spaces as voids surrounding one viewshed. The viewshed like an isovist or visibility graph on map depicts convexity, but with an image collage of fronts and voids (surrounding buildings and streets) distorted on a map. The urban envelope is used as an urban design drawing board in a new software for City Information Modelling (CIM) that is under development. This paper aims to inspire synergetic ways to juxtapose morphological and urban design traditions to discuss applications of morphological theories and urban design practices.