Difference between revisions of "Spherical Normal maps"

From Second Life Wiki
Jump to navigation Jump to search
m (sorting paragraphs, fixing and cutting)
 
(4 intermediate revisions by 2 users not shown)
Line 1: Line 1:
Normal maps for spherical prims/faces and spherical sculpted prims [[PRIM_SCULPT_TYPE_SPHERE]] are different and involve some more/different steps: [http://i.imgur.com/g1hm0cz.jpg]
Normal maps are different between flat faces, Spherical prim faces and Sculpted Prims. Spherical prim faces require a rotation by 90° that can be tricky for some textures, like normal maps for spherical globes:


----
== Planar sculpt maps work just fine on all [[PRIM_SCULPT_TYPE_SPHERE]] sculpted prims, but they do not work on prim spheres ==
 
[http://secondlife.com/app/image/3e9211d6-c42d-a9ff-95b9-5c1ab349ed38/2 3e9211d6-c42d-a9ff-95b9-5c1ab349ed38] will NOT work on prim spheres because they have their poles on the left and right side of an unrotated texture. But rotating a normal map changes the normal map, rotating a normal map by 180° inverts it.


==  Your texture must be rotated 90° sideways to work with a spherical prim and SCULPT_TYPE_SPHERE: ==
Using .werkkzeug3 [https://mega.co.nz/#!s0UHSKTJ!BqybVjWr8wdfYTNePdS5bhonAJkZh3P_2YAvPEtCvVU] to make maps for spherical prims from a height map needs the following command chain:


'''To work on a spherical prim, the height map for your normal map needs to be rotated rotated by 90°''' counter clockwise before you turn it into a normal map. (90° clockwise may work as well) Otherwise the north pole of an earth map on a spherical prim would not be on the pole of a spherical prim face! You can not rotate a normal map on a prim in post without changing the way that it reflects light. A 180° rotation of a normal map within SL turns a hill into a valley!
(double right klick in the lower window to add a function, they are chained from top to bottom loke these functions:)
This also applies for [[PRIM_SCULPT_TYPE_SPHERE]] spherical sculpted prims.


A bump/hill on your (unfinished) normal map should have green on the upper side, blue on the left side and flat terrain should be bright red. This map would work nicely on a flat texture. But it will not work on spherical faces.
* Import: (a .png height map image that has the north pole facing up and that has high parts white and low parts black)
* Rotate: With "angle" set to -0.250, rotating 90° to the right!
* Normal: 3d (flat will be red, hills are green on the lower side)
* HSCB: With 0.600 as "hue" parameter, making "flat" BLUE.
* Rotate: With "angle" set to 0.250, rotating 90° to the left.


----
----


== A [[PRIM_TYPE_SPHERE]] normal map for a sphere prim must be rotated by 90°:==
but green must still be on the upper side of a hill like here: [http://secondlife.com/app/image/ab6adc27-e101-9d3a-1097-088104c1f607/2 ab6adc27-e101-9d3a-1097-088104c1f607]


== All spherical normal maps need hue-shifted (by -90 if "flat" is bright red": ==


''' To work on a spherical face or on a (spherical) sculpted prim, a normal maps image needs to be shifted in its HUE by -90''', -1/4 of a full hue rotation.
Using .werkkzeug3 to make these normal maps for spherical prims needs the following command chain:


Flat terrain should now be purple, the upper left side of a bump should now be green, the upper right side should be red and the lower side should be blue.
* Import: (a .png height map image that has the north pole facing up and that has high parts white and low parts black)
This is necessary for spherical faces/prims and [[PRIM_SCULPT_TYPE_SPHERE]] spherical sculpted prims.
* Normal: 3d (flat will be red, hills are green on the lower side)
* Rotate: With "angle" set to 0.250, rotating 90° to the left.
* HSCB: With 0.600 as "hue" parameter, making "flat" blue.


----
== This Purple-rotated normal map works on sculpt spheres and prim spheres, but not on flat prim faces: ==


== illustrating example: ==
[http://secondlife.com/app/image/1e266b9c-f842-865f-9eb2-39b43e30cb75/2 1e266b9c-f842-865f-9eb2-39b43e30cb75] if good if you like spheres.


A flat normal map (1a6c1313-8042-62cb-8b59-5f30bbfbc47e) on a prim-sphere will have a light source cast no light "south" of it (assuming an earth-map and mostly flat terrain) and have all flat/ocean terrain north of it 100% illuminated.
* Import: (a .png height map image that has the north pole facing up and that has high parts white and low parts black)
* Color: "Mode" set to "invert" (inverting the height map to make high places black and low places white)
* Rotate: With "angle" set to 0.250, rotating 90° to the left.
* Normal: 3d (flat will be red, hills are green on the lower side)
* HSCB: With 0.800 as "hue" parameter, making "flat" PURPLE. (0.8 is correct here, it is purple after all)


A spherical normal map on a prim-sphere (1e266b9c-f842-865f-9eb2-39b43e30cb75) on a sphere will work properly. The same spherical normal map will work on [[PRIM_SCULPT_TYPE_SPHERE]], you just have to rotate the normal map by 270 (or 90) within SL's normal map settings. [http://i.imgur.com/g1hm0cz.jpg]
The normal map must be rotated by 270 in second life.

Latest revision as of 13:09, 28 August 2014

Normal maps are different between flat faces, Spherical prim faces and Sculpted Prims. Spherical prim faces require a rotation by 90° that can be tricky for some textures, like normal maps for spherical globes:

Planar sculpt maps work just fine on all PRIM_SCULPT_TYPE_SPHERE sculpted prims, but they do not work on prim spheres

3e9211d6-c42d-a9ff-95b9-5c1ab349ed38 will NOT work on prim spheres because they have their poles on the left and right side of an unrotated texture. But rotating a normal map changes the normal map, rotating a normal map by 180° inverts it.

Using .werkkzeug3 [1] to make maps for spherical prims from a height map needs the following command chain:

(double right klick in the lower window to add a function, they are chained from top to bottom loke these functions:)

  • Import: (a .png height map image that has the north pole facing up and that has high parts white and low parts black)
  • Rotate: With "angle" set to -0.250, rotating 90° to the right!
  • Normal: 3d (flat will be red, hills are green on the lower side)
  • HSCB: With 0.600 as "hue" parameter, making "flat" BLUE.
  • Rotate: With "angle" set to 0.250, rotating 90° to the left.

A PRIM_TYPE_SPHERE normal map for a sphere prim must be rotated by 90°:

but green must still be on the upper side of a hill like here: ab6adc27-e101-9d3a-1097-088104c1f607


Using .werkkzeug3 to make these normal maps for spherical prims needs the following command chain:

  • Import: (a .png height map image that has the north pole facing up and that has high parts white and low parts black)
  • Normal: 3d (flat will be red, hills are green on the lower side)
  • Rotate: With "angle" set to 0.250, rotating 90° to the left.
  • HSCB: With 0.600 as "hue" parameter, making "flat" blue.

This Purple-rotated normal map works on sculpt spheres and prim spheres, but not on flat prim faces:

1e266b9c-f842-865f-9eb2-39b43e30cb75 if good if you like spheres.

  • Import: (a .png height map image that has the north pole facing up and that has high parts white and low parts black)
  • Color: "Mode" set to "invert" (inverting the height map to make high places black and low places white)
  • Rotate: With "angle" set to 0.250, rotating 90° to the left.
  • Normal: 3d (flat will be red, hills are green on the lower side)
  • HSCB: With 0.800 as "hue" parameter, making "flat" PURPLE. (0.8 is correct here, it is purple after all)

The normal map must be rotated by 270 in second life.

Retrieved from "https://wiki.secondlife.com/w/index.php?title=Spherical_Normal_maps&oldid=1193101"