Urho3D ProcGeom

NOTE: Image, IndexBuffer, and Drawable only contain one addition each: DrawLine, SetDataOptimal (converts 32-bit to 16-bit indices if possible), and WriteGeometryToOBJ.

Procedural geometry utilities for Urho3D.

• Lathe
  • ParShapes based surface of revolution
• Loft
  • Extrude a 2d profile through a series of oriented points
  • No caps
• Spine Loft
  • Assumes the natural up axis is Y
  • anchor to zero for caps
• Carve CSG
  • Helpers for one-off add / subtract / intersect
  • UDIM-like UV coordinate offsets for texture-array packing
• DirectX UV-Atlas
  • Automatic chartings
• Misc Tools
  • Anchoring a list of points to a range
    • Split 50/50 adjust to floor and ceiling
    • Anchor to ceiling (crown-molding)
    • Anchor to floor (base-boards / floor-trim)
  • Render UV layout to Image
    • Only change in Image.h / Image.cpp
  • Compile static shadow-geometry
    • Merged and reduced to canonicals only
  • Write list of Geometry to OBJ
    • Only change in Drawable.h / Drawable.cpp
  • CalculateNormals like the existing calculate tangents
  • Geometry transform helpers
    • Make vertices unique
    • Convert between different vertex layouts
    • basic transforms
    • UV coordinate offsets/transforms
• UDMF Loading
  • Requires MathGeoLib: for Polygon
  • Requires forked of GZDoomBuilder to do the exporting
  • Not the actual UDMF format (weird right)
    • Might read actual UDMF someday, some work on a generic lexer in there for it
  • Primary purpose is a source for guiding or reference data to do other procedural things with
  • A few transformations
    • Align edges (move and rotate to line up)
    • remove sectors
    • center the map
    • flip, translate, and rotate

Example Output

Here the UDMF data for Doom2 MAP01 has been refined using spine-lofts along the walls and lathe objects on corners exceeding a threshold to insert columns.

Changing the 2d profiles used for either quickly changes the feel of the refined mesh.

Generating UV Images

Wireframes are useful for figuring out how to layout textures for lofts and lathes.

Loading UDMF (drawing the overhead)

UV Generation

DX-UV Atlas for automatic UV charting.

Dependencies

• Carve
• ParShapes (for lathe)
  • Used for merge colocals in the lathe function
• LibIGL
  • Not strict until Laplacian processes are fully ported over
• Eigen
  • For LibIGL
  • WARNING: some of the LibIGL using parts rely on Eigen/unsupported/Eigen/...
    • DON'T FORGET TO SET THAT UP FOR INCLUDE PATH ACCESS
• MathGeoLib
  • For UDMF only

Works in progress

• Laplacian deformation
  • Need to port over from MathGeoLib dependent version
  • Untested, method-changed from original version
  • possibly dropping for IGL harmonics
• LOD Generation
  • via libigl::decimate
  • Seam-Aware Decimater is being considered, but has issues with real-world use
    • mapping other vertex data (bone-weights, etc)
    • May add as an option just for statics where normals and tangents can safely be recalculated
• Bone-glow automatic weights
  • Need to port over from MathGeoLib dependent version
  • Untested
• Auto UVs
  • Tested and works
• CGA-like volume grammar
  • sorting out license issues