GL_NV_texgen_emboss
https://www.khronos.org/registry/OpenGL/extensions/NV/NV_texgen_emboss.txt
GL_NV_texgen_emboss

	GL_EMBOSS_LIGHT_NV 0x855D
	GL_EMBOSS_CONSTANT_NV 0x855E
	GL_EMBOSS_MAP_NV 0x855F