Implement additional draw modes:

- Default rendering but without textures.
- Island coloring based on sleep state.
- Selected object highlighting.

PiperOrigin-RevId: 928482603
Change-Id: I5eda1307bc6e71a4b0b2933b5b941e945cb9de75

src/experimental/filament/filament/renderable.cc

@@ -34,6 +34,7 @@
 #include <math/vec4.h>
 #include <utils/EntityManager.h>
 #include <mujoco/mujoco.h>
+#include "engine/engine_vis_visualize.h"
 #include "experimental/filament/filament_util.h"
 #include "experimental/filament/filament/builtins.h"
 #include "experimental/filament/filament/material_manager.h"
@@ -270,6 +271,40 @@ void Renderable::Prepare(std::span<const mjrRenderRequest*> requests,
       material.segmentation_id = 0;
     }
 
+    if (request->draw_mode == mjDRAW_MODE_ISLANDS &&
+        material.sleep_state != mjS_STATIC) {
+      float hue = 1.0f;
+      float saturation = 0.0f;
+      float value = 0.7f;
+      if (material.island_id >= 0) {
+        const double h = static_cast<double>(material.island_id) + 1.0;
+        hue = mju_Halton(h, 7);
+        saturation = 0.5 + 0.5 * mju_Halton(h, 3);
+        value = 0.6 + 0.4 * mju_Halton(h, 5);
+      }
+      if (material.sleep_state == mjS_ASLEEP) {
+        value *= 0.6;
+        saturation *= 0.7;
+      }
+      hsv2rgb(material.color, hue, saturation, value);
+      material.color[3] = 1;
+
+      // Remove textures so they don't interfere with the island color.
+      material.color_texture = nullptr;
+      material.metallic_texture = nullptr;
+      material.roughness_texture = nullptr;
+      material.occlusion_texture = nullptr;
+      material.orm_texture = nullptr;
+    }
+
+    if (request->draw_mode == mjDRAW_MODE_DEFAULT_NO_TEXTURES) {
+      material.color_texture = nullptr;
+      material.metallic_texture = nullptr;
+      material.roughness_texture = nullptr;
+      material.occlusion_texture = nullptr;
+      material.orm_texture = nullptr;
+    }
+
     const bool reflective = request->draw_mode == mjDRAW_MODE_DEFAULT &&
                             request->enable_reflections &&
                             material.reflectance > 0.0;
@@ -278,6 +313,10 @@ void Renderable::Prepare(std::span<const mjrRenderRequest*> requests,
           this, request->viewport.width, request->viewport.height);
     }
 
+    if (material.selected) {
+      material.emissive += 0.3f;  // vis->global.glow
+    }
+
     const Mesh* mesh = !parts_.empty() ? parts_[0].mesh : nullptr;
     draw_state.material_key = material_mgr_->PrepareMaterialInstance(
         material, request->draw_mode, geom_type_, mesh);

src/experimental/filament/render_context_filament.cc

@@ -81,6 +81,8 @@ void mjr_defaultMaterial(mjrMaterial* material) {
   memset(material, 0, sizeof(mjrMaterial));
   setf(material->color, {1.f, 1.f, 1.f, 1.f});
   setf(material->uv_scale, {1, 1, 1});
+  material->sleep_state = mjS_STATIC;
+  material->island_id = -1;
   material->emissive = -1.0f;
   material->specular = -1.0f;
   material->glossiness = -1.0f;

src/experimental/filament/render_context_filament.h

@@ -129,10 +129,14 @@ void mjrf_destroyContext(mjrfContext* ctx);
 typedef enum mjrDrawMode_ {
   // Render the scene with default settings for colors and lighting (shading).
   mjDRAW_MODE_DEFAULT,
+  // Like mjDRAW_MODE_DEFAULT, but disable textures.
+  mjDRAW_MODE_DEFAULT_NO_TEXTURES,
   // Render the scene as a wireframe.
   mjDRAW_MODE_WIREFRAME,
   // Render the scene as a grayscale depth map.
   mjDRAW_MODE_DEPTH,
+  // Render each object using its.
+  mjDRAW_MODE_ISLANDS,
   // Render each object using its segmentation id (see mjrMaterial).
   mjDRAW_MODE_SEGMENTATION_BY_ID,
   // Render each object with a unique color based on its segmentation id.
@@ -600,6 +604,10 @@ struct mjrMaterial {
   // RGB8 color, so only the first 24 bits are used.
   int32_t segmentation_id;
 
+  // The island ID and sleep state.
+  int32_t island_id;
+  mjtSleepState sleep_state;
+
   // Applies an addition scale to the UV coordinates of the object. Defaults to
   // (1, 1, 1).
   float uv_scale[3];
@@ -630,6 +638,10 @@ struct mjrMaterial {
   // used for UX or decorative elements like contact forces and labels.
   mjtByte decor_ux;
 
+  // If true, renders the object such that it appears "selected" for the
+  // purposes of UX visualization.
+  mjtByte selected;
+
   // The texture containing the base color of the object.
   const mjrTexture* color_texture;