ADD UPDATE (PEPAKURA, PLUS MODELING TIPS)...
The Halo 5 Interceptor helmet for pepakura has been added to the beginning of the thread (and below).
Halo 5 helmet interceptor asset mod (Satchmo III) 2018-06-10.pdo
I wanted to share some info on the choices I make when converting game asset models for pepakura use (most of the same principals apply to when modeling from photo references). This is not a modeling tutorial exactly and doesn't delve greatly into specific modeling software/tools, but it may be helpful for those interested in learning about or improving their skills for preparing game asset (or original) meshes for pepakura.
It should go without saying but there is no correct path and what I describe below is just what works for me and what I believe makes effective models for the pepakura process. There is no easy button whether you work with game assets or from image references...time and consideration are your friends for producing good output. You can find a wealth of modeling tutorials on YouTube or other forums for your chosen modeling software (especially Blender).
I describe my choices below and point them out on the following image reference which includes photos of the game asset at the left and photos of my revised model at the right. General notes don't have an accompanying call-out on the reference image.
If you have any questions or suggestions please feel free to share.
1) Start by deleting half of the model and use a mirroring function (mirror modifier in Blender) along the center-line.
A) [GEN NOTE] This reduces the workload (actions made on one side automatically mirror on the other) and ensures symmetry.
B) May have to split faces if edges don't exist along center-line.
C) [GEN NOTE] A symmetrical model with center-line at zero on the X axis allows the mirror-point function to be used in Pepakura Designer (open edges specified on one side are automatically mirrored on the other side).
2) Convert most triangles to quadrilaterals, but use tris where needed/desired.
A) [GEN NOTE] This provides a cleaner view of model (better to see the overall form).
B) [GEN NOTE] This simplifies the unfold process in Pepakura Designer by limiting cut options.
C) Tris can be used effectively where needing to reduce reduce geometry along surfaces.
D) [GEN NOTE] Software can automatically convert tris into quads, but this doesn't always pick the best tris to convert to quads, so manual clean up is necessary.
3) Remove or modify details not desirable or not suitable for pepakura.
A) Often the smallest details are separate meshes not connected to the main mesh and can just be deleted.
B) Some details are part of the main mesh and geometry must be modified to simplify or remove.
C) Faces that are very skinny can be exaggerated or widened (this makes paper assembly less tedious and provides greater surface area for gluing paper tabs).
D) Some parts may not be connected to the main mesh but may want to be retained.
> Such as the visor, which is typically separate in game assets, or sometimes other parts like called out below.
> To retain, the number of edges/verts must be made to match the geometry of the main mesh so they can be mated.
4) Modify edge-flow to better approximate curved surfaces.
A) In this example, the edge-flow of the simplified model better follows the curve of the forehead surface.
B) In this example, spreading out the edges helps to better define the flatter surface (and larger faces will help to ensure paper is easier to put together).
C) [GEN NOTE] Geometry can be added/removed to improve edge-flow. Edges should generally be spaced apart a consistent amount.
5) Modify the helmet opening.
A) Make an opening (if needed) and create a ring of faces of consistent width around the opening.
B) Extend another ring up into the helmet to create "depth," this also adds physical structure to the opening.
C) Widen the opening as much as affordable to accommodate insertion of a head. The opening on game models are often smaller than necessary for actual heads since computer characters aren't concerned about squeezing their noggins into the helmets.
Thanks for reading. Take care four-oh-five.
