Thursday, March 3, 2016

Lazy Lady's 10 minute Add Sculpt Detail to a Model Process in Cycles

Another reason to use cycles for the after effects process.  Hi poly to Lo poly is much easier to manage.  I call the example here the lazy lady's way to add faux polygons to a model.  The Hi poly sculpt (done very quickly for the purpose of this demo) is 77,015 triangles, while the Lo poly version is 252 triangles (subdivided twice).  I use this process often for adding detail to environmental objects and terrain.  Albeit, in this example the ears of my head sculpt were not considered by the normal baking process.  For that to occur I would need to do a simple retopo, but most of the detail in this example did transfer without any retopo.  When its not necessary why go to all that trouble?
So how it *easily gets done follows:

*easily is in the hands of the builder.  I baked maps in Blender Render, but the normal Hi to Lo baking process (with my computer) is a fickle one.  The results vary.  When I use cycles it never varies and always works well with retopo models or my lazy lady's versions.

Lady Lady LO poly -  No retopo
HI poly retopo - no unwrapping required
1.  Added a box modeled sphere and subdivision modifier to create a 2 subdivided 250+ model.  I slightly scaled up (inflated) the model to better cover the HI poly, while realizing that an even better LO poly model would benefit by retopology (built after sculpting the Hi poly model to account for the hair and ears).  I did not choose the latter for this model, because I often need far less detail for terrain or other OS storybuild objects.  The Lo poly model needs to be renamed and added to the layer just below the HI poly model layer so it can be easily accessed.

2. Sculpted HI Poly 77,000+ model (not pretty but fine for an example).  Used multiresolution modifier to prepare surface and dynamic topology to add sculpt detail.  My machine much prefers dynamic topology to additional multi subdivides.  The good news is there no need to unwrap or add a material.  The model is not going to be around that long.  Be sure to add it to a layer you can easily find like layer upper left 1. Be sure to name it HI poly, so that you can find it in the outliner.  Much easier to manage from that panel. The Lo poly model needs to be unwrapped.  The material and cycle nodes are added to the nodes editor:  For the transfer process the only nodes required are the connected diffuse and output, plus the one stand alone image texture node loaded with a new image for the normal map baking.

Lo poly after transfer
 3.  Finally the transfer steps. In object mode and from the outliner choose the HI poly model first, then the LO poly.  You will know it worked, because the LO poly nodes appear in the editor.  Now choose bake from the render panel.  Look to see that selected to active is checked and the ray distance is set to 1.000.  The baking time should not take long.  Your map in the uv image editor will turn into a normal map that you can now add to your favorite texture set up for the Lo poly model.  And/or you can take it into world and add it to your texture.  When the map is attached in cycles I can adjust the strength.  In world not so much.  So I make two versions while I am at it.  The low strength version usually works better in world.  If I use one at all?  It does use a resource offset.