Update

acronym.md

@@ -18,6 +18,7 @@ Here is a list of some acronyms:
 - **[ANCAP](ancap.md)** (anarcho capitalist)
 - **[ANPAC](anpac.md)** (anarcho pacifist)
 - **[ANSI](ansi.md)** (american national standards institute)
+- **[AO](ao.md)** (ambient occlusion)
 - **[API](api.md)** (application programming interface)
 - **[ARM](arm.md)** (advanced [RISC](risc.md) machines)
 - **[ARPANET](arpanet.md)** (advanced research projects agency network)
@@ -58,6 +59,7 @@ Here is a list of some acronyms:
 - **[CPU](cpu.md)** (central processing unit)
 - **[CRC](crc.md)** (cyclic redundancy check)
 - **[CRT](crt.md)** (cathode ray tube)
+- **[CSG](csg.md)** (constructive solid geometry)
 - **[CSS](css.md)** (cascading style sheet)
 - **[CSV](csv.md)** (comma separated values)
 - **[DAC](dac.md)** (digital analog converter)
@@ -112,6 +114,7 @@ Here is a list of some acronyms:
 - **[GBPS](gbps.md)** (GB per second)
 - **[GCC](gcc.md)** (GNU compiler collection)
 - **[GDB](gdb.md)** (GNU debugger)
+- **[GI](gi.md)** (global illumination)
 - **[GIB](gib.md)** (gibibyte)
 - **[GIF](gif.md)** (graphics interchange format)
 - **[GIGO](gigo.md)** (garbage in garbage out)
@@ -240,6 +243,7 @@ Here is a list of some acronyms:
 - **[OSI](osi.md)** ([open source](open_source.md) initiative)
 - **[P2P](p2p.md)** (peer to peer)
 - **[PB](pb.md)** (petabyte, petabit, personal best)
+- **[PBR](pbr.md)** (physically based rendering)
 - **[PC](pc.md)** (personal computer, political correctness)
 - **[PD](pd.md)** ([public domain](public_domain.md))
 - **[PDF](pdf.md)** (portable document format)
@@ -281,6 +285,7 @@ Here is a list of some acronyms:
 - **[SAF](saf.md)** (smallabstractfish)
 - **[SCL](smallchesslib)** (smallchesslib)
 - **[SD](sd.md)** (standard definition, secure digital)
+- **[SDF](sdf.md)** (signed distance function)
 - **[SDK](sdk.md)** (software development kit)
 - **[SDL](sdl.md)** (simple directmedia layer)
 - **[SEO](seo.md)** (search engine optimization)