diff --git a/libs/yocto/yocto_raytracing.cpp b/libs/yocto/yocto_raytracing.cpp
index 832e80bcb..fb59a886a 100644
--- a/libs/yocto/yocto_raytracing.cpp
+++ b/libs/yocto/yocto_raytracing.cpp
@@ -992,11 +992,11 @@ static vec4f shade_raytrace(const scene_data& scene, const scene_bvh& bvh,
 
   // evaluate geometry
   auto& instance = scene.instances[intersection.instance];
-  auto  position = eval_position(
+  auto  position = instance_point(
       scene, instance, intersection.element, intersection.uv);
-  auto normal = eval_normal(
+  auto normal = instance_normal(
       scene, instance, intersection.element, intersection.uv);
-  auto texcoord = eval_texcoord(
+  auto texcoord = instance_texcoord(
       scene, instance, intersection.element, intersection.uv);
   auto outgoing = -ray.d;
 
@@ -1106,11 +1106,11 @@ static vec4f shade_matte(const scene_data& scene, const scene_bvh& bvh,
 
   // evaluate geometry
   auto& instance = scene.instances[intersection.instance];
-  auto  position = eval_position(
+  auto  position = instance_point(
       scene, instance, intersection.element, intersection.uv);
-  auto normal = eval_normal(
+  auto normal = instance_normal(
       scene, instance, intersection.element, intersection.uv);
-  auto texcoord = eval_texcoord(
+  auto texcoord = instance_texcoord(
       scene, instance, intersection.element, intersection.uv);
 
   // evaluate material
@@ -1150,11 +1150,11 @@ static vec4f shade_pointlight(const scene_data& scene, const scene_bvh& bvh,
 
   // evaluate geometry
   auto& instance = scene.instances[intersection.instance];
-  auto  position = eval_position(
+  auto  position = instance_point(
       scene, instance, intersection.element, intersection.uv);
-  auto normal = eval_normal(
+  auto normal = instance_normal(
       scene, instance, intersection.element, intersection.uv);
-  auto texcoord = eval_texcoord(
+  auto texcoord = instance_texcoord(
       scene, instance, intersection.element, intersection.uv);
   auto outgoing = -ray.d;
 
@@ -1208,11 +1208,11 @@ static vec4f shade_arealight(const scene_data& scene, const scene_bvh& bvh,
 
   // evaluate geometry
   auto& instance = scene.instances[intersection.instance];
-  auto  position = eval_position(
+  auto  position = instance_point(
       scene, instance, intersection.element, intersection.uv);
-  auto normal = eval_normal(
+  auto normal = instance_normal(
       scene, instance, intersection.element, intersection.uv);
-  auto texcoord = eval_texcoord(
+  auto texcoord = instance_texcoord(
       scene, instance, intersection.element, intersection.uv);
 
   // evaluate material
@@ -1280,9 +1280,9 @@ static vec4f shade_eyelight(const scene_data& scene, const scene_bvh& bvh,
 
   // evaluate geometry
   auto& instance = scene.instances[intersection.instance];
-  auto  normal   = eval_normal(
+  auto  normal   = instance_normal(
       scene, instance, intersection.element, intersection.uv);
-  auto texcoord = eval_texcoord(
+  auto texcoord = instance_texcoord(
       scene, instance, intersection.element, intersection.uv);
   auto outgoing = -ray.d;
 
@@ -1308,7 +1308,7 @@ static vec4f shade_normal(const scene_data& scene, const scene_bvh& bvh,
 
   // prepare shading point
   auto& instance = scene.instances[intersection.instance];
-  auto  normal   = eval_normal(
+  auto  normal   = instance_normal(
       scene, instance, intersection.element, intersection.uv);
 
   auto radiance = normal * 0.5f + 0.5f;
@@ -1326,7 +1326,7 @@ static vec4f shade_texcoord(const scene_data& scene, const scene_bvh& bvh,
 
   // prepare shading point
   auto& instance = scene.instances[intersection.instance];
-  auto  texcoord = eval_texcoord(
+  auto  texcoord = instance_texcoord(
       scene, instance, intersection.element, intersection.uv);
   texcoord = {fmod(texcoord.x, 1), fmod(texcoord.y, 1)};
 
diff --git a/libs/yocto/yocto_raytracing.h b/libs/yocto/yocto_raytracing.h
index 3d2909551..309076bb4 100644
--- a/libs/yocto/yocto_raytracing.h
+++ b/libs/yocto/yocto_raytracing.h
@@ -728,42 +728,42 @@ namespace yocto {
 // Convenience functions
 inline vec3f intersection_point(
     const scene_data& scene, const intersection3f& intersection) {
-  return eval_position(scene, scene.instances[intersection.instance],
+  return instance_point(scene, scene.instances[intersection.instance],
       intersection.element, intersection.uv);
 }
 inline vec3f intersection_normal(
     const scene_data& scene, const intersection3f& intersection) {
-  return eval_normal(scene, scene.instances[intersection.instance],
+  return instance_normal(scene, scene.instances[intersection.instance],
       intersection.element, intersection.uv);
 }
 inline vec3f intersection_element_normal(
     const scene_data& scene, const intersection3f& intersection) {
-  return eval_element_normal(
+  return instance_element_normal(
       scene, scene.instances[intersection.instance], intersection.element);
 }
 inline vec3f intersection_shading_point(const scene_data& scene,
     const intersection3f& intersection, vec3f outgoing) {
-  return eval_shading_position(scene, scene.instances[intersection.instance],
+  return instance_shading_point(scene, scene.instances[intersection.instance],
       intersection.element, intersection.uv, outgoing);
 }
 inline vec3f intersection_shading_normal(const scene_data& scene,
     const intersection3f& intersection, vec3f outgoing) {
-  return eval_shading_normal(scene, scene.instances[intersection.instance],
+  return instance_shading_normal(scene, scene.instances[intersection.instance],
       intersection.element, intersection.uv, outgoing);
 }
 inline vec2f intersection_texcoord(
     const scene_data& scene, const intersection3f& intersection) {
-  return eval_texcoord(scene, scene.instances[intersection.instance],
+  return instance_texcoord(scene, scene.instances[intersection.instance],
       intersection.element, intersection.uv);
 }
 inline material_point intersection_material(
     const scene_data& scene, const intersection3f& intersection) {
-  return eval_material(scene, scene.instances[intersection.instance],
+  return instance_material(scene, scene.instances[intersection.instance],
       intersection.element, intersection.uv);
 }
 inline bool is_volumetric_intersection(
     const scene_data& scene, const intersection3f& intersection) {
-  return is_volumetric(scene, scene.instances[intersection.instance]);
+  return is_volumetric_instance(scene, scene.instances[intersection.instance]);
 }
 
 }  // namespace yocto
diff --git a/libs/yocto/yocto_scene.cpp b/libs/yocto/yocto_scene.cpp
index 35a66a368..519a57a2a 100644
--- a/libs/yocto/yocto_scene.cpp
+++ b/libs/yocto/yocto_scene.cpp
@@ -864,7 +864,7 @@ bool has_volume(const material_point& material) {
 namespace yocto {
 
 // Eval position
-vec3f eval_position(const scene_data& scene, const instance_data& instance,
+vec3f instance_point(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv) {
   auto& shape = scene.shapes[instance.shape];
   if (!shape.triangles.empty()) {
@@ -890,7 +890,7 @@ vec3f eval_position(const scene_data& scene, const instance_data& instance,
 }
 
 // Shape element normal.
-vec3f eval_element_normal(
+vec3f instance_element_normal(
     const scene_data& scene, const instance_data& instance, int element) {
   auto& shape = scene.shapes[instance.shape];
   if (!shape.triangles.empty()) {
@@ -915,11 +915,11 @@ vec3f eval_element_normal(
 }
 
 // Eval normal
-vec3f eval_normal(const scene_data& scene, const instance_data& instance,
+vec3f instance_normal(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv) {
   auto& shape = scene.shapes[instance.shape];
   if (shape.normals.empty())
-    return eval_element_normal(scene, instance, element);
+    return instance_element_normal(scene, instance, element);
   if (!shape.triangles.empty()) {
     auto t = shape.triangles[element];
     return transform_normal(
@@ -944,7 +944,7 @@ vec3f eval_normal(const scene_data& scene, const instance_data& instance,
 }
 
 // Eval texcoord
-vec2f eval_texcoord(const scene_data& scene, const instance_data& instance,
+vec2f instance_texcoord(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv) {
   auto& shape = scene.shapes[instance.shape];
   if (shape.texcoords.empty()) return uv;
@@ -999,7 +999,7 @@ static pair<vec3f, vec3f> eval_tangents(
 #endif
 
 // Shape element normal.
-pair<vec3f, vec3f> eval_element_tangents(
+pair<vec3f, vec3f> instance_element_tangents(
     const scene_data& scene, const instance_data& instance, int element) {
   auto& shape = scene.shapes[instance.shape];
   if (!shape.triangles.empty() && !shape.texcoords.empty()) {
@@ -1022,18 +1022,18 @@ pair<vec3f, vec3f> eval_element_tangents(
   }
 }
 
-vec3f eval_normalmap(const scene_data& scene, const instance_data& instance,
+vec3f instance_normalmap(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv) {
   auto& shape    = scene.shapes[instance.shape];
   auto& material = scene.materials[instance.material];
   // apply normal mapping
-  auto normal   = eval_normal(scene, instance, element, uv);
-  auto texcoord = eval_texcoord(scene, instance, element, uv);
+  auto normal   = instance_normal(scene, instance, element, uv);
+  auto texcoord = instance_texcoord(scene, instance, element, uv);
   if (material.normal_tex != invalidid &&
       (!shape.triangles.empty() || !shape.quads.empty())) {
     auto& normal_tex = scene.textures[material.normal_tex];
     auto  normalmap  = -1 + 2 * xyz(eval_texture(normal_tex, texcoord, true));
-    auto [tu, tv]    = eval_element_tangents(scene, instance, element);
+    auto [tu, tv]    = instance_element_tangents(scene, instance, element);
     auto frame       = frame3f{tu, tv, normal, {0, 0, 0}};
     frame.x          = orthonormalize(frame.x, frame.z);
     frame.y          = normalize(cross(frame.z, frame.x));
@@ -1045,34 +1045,34 @@ vec3f eval_normalmap(const scene_data& scene, const instance_data& instance,
 }
 
 // Eval shading position
-vec3f eval_shading_position(const scene_data& scene,
+vec3f instance_shading_point(const scene_data& scene,
     const instance_data& instance, int element, vec2f uv, vec3f outgoing) {
   auto& shape = scene.shapes[instance.shape];
   if (!shape.triangles.empty() || !shape.quads.empty()) {
-    return eval_position(scene, instance, element, uv);
+    return instance_point(scene, instance, element, uv);
   } else if (!shape.lines.empty()) {
-    return eval_position(scene, instance, element, uv);
+    return instance_point(scene, instance, element, uv);
   } else if (!shape.points.empty()) {
-    return eval_position(scene, instance, element, uv);
+    return instance_point(scene, instance, element, uv);
   } else {
     return {0, 0, 0};
   }
 }
 
 // Eval shading normal
-vec3f eval_shading_normal(const scene_data& scene,
+vec3f instance_shading_normal(const scene_data& scene,
     const instance_data& instance, int element, vec2f uv, vec3f outgoing) {
   auto& shape    = scene.shapes[instance.shape];
   auto& material = scene.materials[instance.material];
   if (!shape.triangles.empty() || !shape.quads.empty()) {
-    auto normal = eval_normal(scene, instance, element, uv);
+    auto normal = instance_normal(scene, instance, element, uv);
     if (material.normal_tex != invalidid) {
-      normal = eval_normalmap(scene, instance, element, uv);
+      normal = instance_normalmap(scene, instance, element, uv);
     }
     if (material.type == material_type::refractive) return normal;
     return dot(normal, outgoing) >= 0 ? normal : -normal;
   } else if (!shape.lines.empty()) {
-    auto normal = eval_normal(scene, instance, element, uv);
+    auto normal = instance_normal(scene, instance, element, uv);
     return orthonormalize(outgoing, normal);
   } else if (!shape.points.empty()) {
     return outgoing;
@@ -1082,7 +1082,7 @@ vec3f eval_shading_normal(const scene_data& scene,
 }
 
 // Eval color
-vec4f eval_color(const scene_data& scene, const instance_data& instance,
+vec4f instance_color(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv) {
   auto& shape = scene.shapes[instance.shape];
   if (shape.colors.empty()) return {1, 1, 1, 1};
@@ -1105,14 +1105,14 @@ vec4f eval_color(const scene_data& scene, const instance_data& instance,
 }
 
 // Evaluate material
-material_point eval_material(const scene_data& scene,
+material_point instance_material(const scene_data& scene,
     const instance_data& instance, int element, vec2f uv) {
   auto& material = scene.materials[instance.material];
-  auto  texcoord = eval_texcoord(scene, instance, element, uv);
+  auto  texcoord = instance_texcoord(scene, instance, element, uv);
 
   // evaluate textures
   auto emission_tex  = eval_texture(scene, material.emission_tex, texcoord);
-  auto color_shp     = eval_color(scene, instance, element, uv);
+  auto color_shp     = instance_color(scene, instance, element, uv);
   auto color_tex     = eval_texture(scene, material.color_tex, texcoord);
   auto roughness_tex = eval_texture(
       scene, material.roughness_tex, texcoord, true);
@@ -1156,7 +1156,8 @@ material_point eval_material(const scene_data& scene,
 }
 
 // check if an instance is volumetric
-bool is_volumetric(const scene_data& scene, const instance_data& instance) {
+bool is_volumetric_instance(
+    const scene_data& scene, const instance_data& instance) {
   return is_volumetric(scene.materials[instance.material]);
 }
 
diff --git a/libs/yocto/yocto_scene.h b/libs/yocto/yocto_scene.h
index a0333eb30..e1358a96c 100644
--- a/libs/yocto/yocto_scene.h
+++ b/libs/yocto/yocto_scene.h
@@ -443,30 +443,31 @@ bool is_volumetric(const scene_data& scene, const instance_data& instance);
 namespace yocto {
 
 // Evaluate instance properties
-vec3f eval_position(const scene_data& scene, const instance_data& instance,
+vec3f instance_point(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv);
-vec3f eval_element_normal(
+vec3f instance_element_normal(
     const scene_data& scene, const instance_data& instance, int element);
-vec3f eval_normal(const scene_data& scene, const instance_data& instance,
+vec3f instance_normal(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv);
-vec2f eval_texcoord(const scene_data& scene, const instance_data& instance,
+vec2f instance_texcoord(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv);
-pair<vec3f, vec3f> eval_element_tangents(
+pair<vec3f, vec3f> instance_element_tangents(
     const scene_data& scene, const instance_data& instance, int element);
-vec3f eval_normalmap(const scene_data& scene, const instance_data& instance,
+vec3f instance_normalmap(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv);
-vec3f eval_shading_position(const scene_data& scene,
+vec3f instance_shading_point(const scene_data& scene,
     const instance_data& instance, int element, vec2f uv, vec3f outgoing);
-vec3f eval_shading_normal(const scene_data& scene,
+vec3f instance_shading_normal(const scene_data& scene,
     const instance_data& instance, int element, vec2f uv, vec3f outgoing);
-vec4f eval_color(const scene_data& scene, const instance_data& instance,
+vec4f instance_color(const scene_data& scene, const instance_data& instance,
     int element, vec2f uv);
 
 // Eval material to obtain emission, brdf and opacity.
-material_point eval_material(const scene_data& scene,
+material_point instance_material(const scene_data& scene,
     const instance_data& instance, int element, vec2f uv);
 // check if a material has a volume
-bool is_volumetric(const scene_data& scene, const instance_data& instance);
+bool is_volumetric_instance(
+    const scene_data& scene, const instance_data& instance);
 
 }  // namespace yocto
 
diff --git a/libs/yocto/yocto_trace.cpp b/libs/yocto/yocto_trace.cpp
index 1fc498f67..e09d4ecfc 100644
--- a/libs/yocto/yocto_trace.cpp
+++ b/libs/yocto/yocto_trace.cpp
@@ -347,7 +347,7 @@ static vec3f sample_lights(const scene_data& scene, const trace_lights& lights,
     auto& shape     = scene.shapes[instance.shape];
     auto  element   = sample_discrete(light.elements_cdf, rel);
     auto  uv        = (!shape.triangles.empty()) ? sample_triangle(ruv) : ruv;
-    auto  lposition = eval_position(scene, instance, element, uv);
+    auto  lposition = instance_point(scene, instance, element, uv);
     return normalize(lposition - position);
   } else if (light.environment != invalidid) {
     auto& environment = scene.environments[light.environment];
@@ -384,9 +384,9 @@ static float sample_lights_pdf(const scene_data& scene, const trace_bvh& bvh,
             bvh, scene, light.instance, {next_position, direction});
         if (!intersection.hit) break;
         // accumulate pdf
-        auto lposition = eval_position(
+        auto lposition = instance_point(
             scene, instance, intersection.element, intersection.uv);
-        auto lnormal = eval_element_normal(
+        auto lnormal = instance_element_normal(
             scene, instance, intersection.element);
         // prob triangle * area triangle = area triangle mesh
         auto area = light.elements_cdf.back();
@@ -659,10 +659,10 @@ static trace_result trace_pathdirect(const scene_data& scene,
           auto emission =
               !intersection.hit
                   ? environments_emission(scene, incoming)
-                  : eval_emission(eval_material(scene,
+                  : eval_emission(instance_material(scene,
                                       scene.instances[intersection.instance],
                                       intersection.element, intersection.uv),
-                        eval_shading_normal(scene,
+                        instance_shading_normal(scene,
                             scene.instances[intersection.instance],
                             intersection.element, intersection.uv, -incoming),
                         -incoming);
@@ -854,11 +854,11 @@ static trace_result trace_pathmis(const scene_data& scene, const trace_bvh& bvh,
             if (!intersection.hit) {
               emission = environments_emission(scene, incoming);
             } else {
-              auto material = eval_material(scene,
+              auto material = instance_material(scene,
                   scene.instances[intersection.instance], intersection.element,
                   intersection.uv);
               emission      = eval_emission(material,
-                       eval_shading_normal(scene,
+                       instance_shading_normal(scene,
                            scene.instances[intersection.instance],
                            intersection.element, intersection.uv, -incoming),
                        -incoming);
@@ -1069,10 +1069,10 @@ static trace_result trace_lightsampling(const scene_data& scene,
         auto emission =
             !intersection.hit
                 ? environments_emission(scene, incoming)
-                : eval_emission(eval_material(scene,
+                : eval_emission(instance_material(scene,
                                     scene.instances[intersection.instance],
                                     intersection.element, intersection.uv),
-                      eval_shading_normal(scene,
+                      instance_shading_normal(scene,
                           scene.instances[intersection.instance],
                           intersection.element, intersection.uv, -incoming),
                       -incoming);
@@ -1296,9 +1296,10 @@ static trace_result trace_furnace(const scene_data& scene, const trace_bvh& bvh,
     auto& instance = scene.instances[intersection.instance];
     auto  element  = intersection.element;
     auto  uv       = intersection.uv;
-    auto  position = eval_position(scene, instance, element, uv);
-    auto  normal = eval_shading_normal(scene, instance, element, uv, outgoing);
-    auto  material = eval_material(scene, instance, element, uv);
+    auto  position = instance_point(scene, instance, element, uv);
+    auto  normal   = instance_shading_normal(
+        scene, instance, element, uv, outgoing);
+    auto material = instance_material(scene, instance, element, uv);
 
     // handle opacity
     if (material.opacity < 1 && rand1f(rng) >= material.opacity) {