Merge branch 'feature/texture_compression' into 'develop'

texture compression (fixes #40)

Closes #40

See merge request lowkey42/mirrage!13

assets/extensions/rotation_test/materials/rotation_material.003.msf

 {
     "substance_id": "default",
     "albedo_aid": "rotation_material.003_albedo.ktx",
-    "mat_data_aid": "rotation_material.003_mat_data.ktx"
+    "normal_aid": "rotation_material.003_normal.ktx",
+    "brdf_aid": "rotation_material.003_brdf.ktx",
+    "emission_aid": ""
 }

assets/extensions/sponza/materials/sponza_16___Default.msf

-{
-    "substance_id": "default",
-    "albedo_aid": "sponza_16___Default_albedo.ktx",
-    "mat_data_aid": "sponza_16___Default_mat_data.ktx"
-}

assets/extensions/sponza/materials/sponza_16___default.msf

+{
+    "substance_id": "default",
+    "albedo_aid": "sponza_16___default_albedo.ktx",
+    "normal_aid": "sponza_16___default_normal.ktx",
+    "brdf_aid": "sponza_16___default_brdf.ktx",
+    "emission_aid": ""
+}

assets/extensions/sponza/materials/sponza_Material__25.msf

-{
-    "substance_id": "default",
-    "albedo_aid": "sponza_Material__25_albedo.ktx",
-    "mat_data_aid": "sponza_Material__25_mat_data.ktx"
-}

assets/extensions/sponza/materials/sponza_Material__298.msf

-{
-    "substance_id": "default",
-    "albedo_aid": "sponza_Material__298_albedo.ktx",
-    "mat_data_aid": "sponza_Material__298_mat_data.ktx"
-}

assets/extensions/sponza/materials/sponza_Material__57.msf

-{
-    "substance_id": "alphatest",
-    "albedo_aid": "sponza_Material__57_albedo.ktx",
-    "mat_data_aid": "sponza_Material__57_mat_data.ktx"
-}

assets/extensions/sponza/materials/sponza_arch.msf

 {
     "substance_id": "default",
     "albedo_aid": "sponza_arch_albedo.ktx",
-    "mat_data_aid": "sponza_arch_mat_data.ktx"
+    "normal_aid": "sponza_arch_normal.ktx",
+    "brdf_aid": "sponza_arch_brdf.ktx",
+    "emission_aid": ""
 }

assets/extensions/sponza/materials/sponza_bricks.msf

 {
     "substance_id": "default",
     "albedo_aid": "sponza_bricks_albedo.ktx",
-    "mat_data_aid": "sponza_bricks_mat_data.ktx"
+    "normal_aid": "sponza_bricks_normal.ktx",
+    "brdf_aid": "sponza_bricks_brdf.ktx",
+    "emission_aid": ""
 }

assets/extensions/sponza/materials/sponza_ceiling.msf

 {
     "substance_id": "default",
     "albedo_aid": "sponza_ceiling_albedo.ktx",
-    "mat_data_aid": "sponza_ceiling_mat_data.ktx"
+    "normal_aid": "sponza_ceiling_normal.ktx",
+    "brdf_aid": "sponza_ceiling_brdf.ktx",
+    "emission_aid": ""
 }

assets/extensions/sponza/materials/sponza_chain.msf

 {
     "substance_id": "alphatest",
     "albedo_aid": "sponza_chain_albedo.ktx",
-    "mat_data_aid": "sponza_chain_mat_data.ktx"
+    "normal_aid": "sponza_chain_normal.ktx",
+    "brdf_aid": "sponza_chain_brdf.ktx",
+    "emission_aid": ""
 }

assets/extensions/sponza/materials/sponza_column_a.msf

 {
     "substance_id": "default",
     "albedo_aid": "sponza_column_a_albedo.ktx",
-    "mat_data_aid": "sponza_column_a_mat_data.ktx"
+    "normal_aid": "sponza_column_a_normal.ktx",
+    "brdf_aid": "sponza_column_a_brdf.ktx",
+    "emission_aid": ""
 }