Estimator comparison (Veach scene)

.gitignore

@@ -34,3 +34,4 @@ results/.ipynb_checkpoints
 results/estimator_comparison_simple
 results/estimator_comparison_optimization
 results/estimator_comparison_attached_reparam
+results/estimator_comparison_veach

results/Estimator comparison (Veach).ipynb

@@ -0,0 +1,274 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "43337124",
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-07-28T11:40:41.771668Z",
+     "start_time": "2022-07-28T11:40:41.739437Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "import mitsuba as mi\n",
+    "mi.set_variant(\"llvm_ad_rgb\")\n",
+    "import drjit as dr\n",
+    "\n",
+    "import numpy as np\n",
+    "import matplotlib.pyplot as plt\n",
+    "import cmap_diff\n",
+    "%config InlineBackend.figure_formats = ['svg']\n",
+    "%matplotlib inline\n",
+    "\n",
+    "import time\n",
+    "import os\n",
+    "base_dir = 'estimator_comparison_veach'\n",
+    "if not os.path.exists(base_dir):\n",
+    "    os.makedirs(base_dir)\n",
+    "    \n",
+    "mi.Thread.thread().logger().set_log_level(mi.LogLevel.Warn)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "dd6b3dbf",
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-07-28T11:40:42.753437Z",
+     "start_time": "2022-07-28T11:40:42.551628Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "scene = mi.load_file('scenes/veach.xml')\n",
+    "params = mi.traverse(scene)\n",
+    "param_key = 'plates_top.bsdf.alpha.data'\n",
+    "params.keep([param_key])\n",
+    "\n",
+    "roughness_tex = mi.TensorXf(params[param_key])\n",
+    "\n",
+    "diff_methods = [\n",
+    "    'es_detached',\n",
+    "    \n",
+    "    'bs_detached',\n",
+    "    'bs_attached',\n",
+    "    \n",
+    "    'mis_detached_detached',\n",
+    "    'mis_attached_attached',\n",
+    "    'mis_detached_attached',\n",
+    "    'mis_attached_detached',\n",
+    "    \n",
+    "    'bs_detached_diff',\n",
+    "    'mis_detached_detached_diff',\n",
+    "    \n",
+    "    'bs_attached_reparam',\n",
+    "    'mis_attached_attached_reparam',\n",
+    "]\n",
+    "diff_method_names = [\n",
+    "    'Detached emitter sampling',\n",
+    "    \n",
+    "    'Detached BSDF sampling',\n",
+    "    'Attached BSDF sampling (BIASED!)',\n",
+    "    \n",
+    "    'Detached MIS weights, detached BSDF sampling,\\ndetached emitter sampling',\n",
+    "    'Attached MIS weights, attached BSDF sampling,\\ndetached emitter sampling (BIASED!)',\n",
+    "    'Detached MIS weights, attached BSDF sampling,\\ndetached emitter sampling (BIASED!)',\n",
+    "    'Attached MIS weights, detached BSDF sampling,\\ndetached emitter sampling',\n",
+    "    \n",
+    "    'Detached diff. BSDF sampling',\n",
+    "    'Detached MIS weights, detached diff. BSDF sampling,\\ndetached emitter sampling',\n",
+    "    \n",
+    "    'Attached reparam. BSDF sampling',\n",
+    "    'Attached MIS weights, attached reparam. BSDF sampling,\\ndetached emitter sampling'\n",
+    "]\n",
+    "diff_method_spps = [\n",
+    "    128,\n",
+    "    \n",
+    "    128,\n",
+    "    128,\n",
+    "    \n",
+    "    128,\n",
+    "    128,\n",
+    "    128,\n",
+    "    128,\n",
+    "    \n",
+    "    128,\n",
+    "    128,\n",
+    "    \n",
+    "    64,\n",
+    "    64,\n",
+    "]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "c137fe74",
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-07-28T11:38:43.576475Z",
+     "start_time": "2022-07-28T11:38:03.315102Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "# Render a converged primal image and a finite differences gradient image for comparison\n",
+    "# (This might take a while ...)\n",
+    "eps = 1e-3\n",
+    "fd_spp = 2048\n",
+    "\n",
+    "integrator = mi.load_dict({'type': 'path', 'max_depth': 2})\n",
+    "image = mi.render(scene, params, integrator=integrator, seed=0, spp=fd_spp)\n",
+    "outname = \"{}/primal.exr\".format(base_dir)\n",
+    "mi.util.convert_to_bitmap(image, uint8_srgb=False).write(outname)\n",
+    "\n",
+    "roughness_tex_fd = roughness_tex + eps\n",
+    "params[param_key] = roughness_tex_fd\n",
+    "params.update()\n",
+    "\n",
+    "image_fd = mi.render(scene, params, integrator=integrator, seed=0, spp=fd_spp)\n",
+    "outname = \"{}/grad_fd.exr\".format(base_dir)\n",
+    "mi.util.convert_to_bitmap((image_fd - image) / eps, uint8_srgb=False).write(outname)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "1a705a08",
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-07-28T11:41:34.283391Z",
+     "start_time": "2022-07-28T11:40:44.418618Z"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "for method, method_name, spp in zip(diff_methods, diff_method_names, diff_method_spps):\n",
+    "    print(\"* {}\".format(method_name))\n",
+    "    print(\"  spp = {}\".format(spp))\n",
+    "    integrator = mi.load_dict({'type': 'estimator_comparison',\n",
+    "                               'method': method,\n",
+    "                               'reparam_kappa': 1e5,\n",
+    "                               'reparam_rays': 32})\n",
+    "    \n",
+    "    # Diff. input parameter\n",
+    "    pi = mi.Float(0.0)\n",
+    "    dr.enable_grad(pi)\n",
+    "    dr.set_grad(pi, 1.0)\n",
+    "    params[param_key] = roughness_tex + pi\n",
+    "    params.update()\n",
+    "    \n",
+    "    start = time.time()\n",
+    "    \n",
+    "    image_grad = mi.Float(0.0)\n",
+    "    if 'diff' in method:\n",
+    "        # Differential sampling strategy, use antithetic sampling.\n",
+    "        # Note that we use the same seed twice, and use half the number of samples for each pass.\n",
+    "        image = mi.render(scene, params,\n",
+    "                          integrator=integrator, seed=0, spp=spp//2, antithetic_pass=False)\n",
+    "        dr.forward(pi)\n",
+    "        image_grad = dr.grad(image)\n",
+    "    \n",
+    "        params[param_key] = roughness_tex + pi\n",
+    "        params.update()\n",
+    "\n",
+    "        image = mi.render(scene, params,\n",
+    "                          integrator=integrator, seed=0, spp=spp//2, antithetic_pass=True)\n",
+    "        dr.forward(pi)\n",
+    "        image_grad += dr.grad(image)\n",
+    "\n",
+    "        # Average both passes\n",
+    "        image_grad *= 0.5\n",
+    "    else:\n",
+    "        # Produce differentiable rendering\n",
+    "        image = mi.render(scene, params, integrator=integrator, seed=0, spp=spp)\n",
+    "        # And propagate derivatives forwards through it\n",
+    "        dr.forward(pi)\n",
+    "        image_grad = dr.grad(image)\n",
+    "        \n",
+    "    # Save output gradient image\n",
+    "    outname = \"{}/grad_{}.exr\".format(base_dir, method)\n",
+    "    mi.util.convert_to_bitmap(image_grad, uint8_srgb=False).write(outname)\n",
+    "    \n",
+    "    end = time.time()    \n",
+    "    print(\"  took {:.2f} seconds\".format(end - start))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "7315e600",
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2022-07-28T11:44:47.308320Z",
+     "start_time": "2022-07-28T11:44:47.080781Z"
+    },
+    "scrolled": false
+   },
+   "outputs": [],
+   "source": [
+    "# Display images and save PNGs\n",
+    "image_primal = np.array(mi.Bitmap(\"{}/primal.exr\".format(base_dir)))\n",
+    "image_primal = np.clip(image_primal**(1/2.2), 0.0, 1.0) # Crude gamma correction\n",
+    "plt.imsave('{}/primal.jpg'.format(base_dir), image_primal)\n",
+    "\n",
+    "plt.figure()\n",
+    "plt.imshow(image_primal)\n",
+    "plt.axis('off')\n",
+    "plt.title(\"Primal\")\n",
+    "plt.show()\n",
+    "\n",
+    "image_fd = np.array(mi.Bitmap(\"{}/grad_fd.exr\".format(base_dir)))[:, :, 0]\n",
+    "plt.imsave('{}/grad_fd.jpg'.format(base_dir), image_fd, vmin=-20, vmax=+20, cmap='diff')\n",
+    "\n",
+    "plt.figure()\n",
+    "plt.imshow(image_fd, cmap='diff', vmin=-20, vmax=+20)\n",
+    "plt.axis('off')\n",
+    "plt.title(\"Finite differences\")\n",
+    "plt.show()\n",
+    "\n",
+    "for method, method_name in zip(diff_methods, diff_method_names):\n",
+    "    image_grad = np.array(mi.Bitmap(\"{}/grad_{}.exr\".format(base_dir, method)))[:, :, 0]\n",
+    "    plt.imsave('{}/grad_{}.jpg'.format(base_dir, method), image_grad, vmin=-20, vmax=+20, cmap='diff')\n",
+    "    \n",
+    "    plt.figure()\n",
+    "    plt.imshow(image_grad, cmap='diff', vmin=-20, vmax=+20)\n",
+    "    plt.axis('off')\n",
+    "    plt.title(method_name, size=7)\n",
+    "    plt.show()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "a93cc8d2",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.12"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

results/scenes/meshes/veach_floor.obj

@@ -0,0 +1,16 @@
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+v -10 -4.14615 -10
+v -10 -10 -2
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+v  10  10 -2
+v  10  10 -2
+v -10  10 -2
+v -10 -10 -2
+f 1 2 3
+f 4 5 6
+f 7 8 9
+f 10 11 12

results/scenes/meshes/veach_plates_bottom.obj

@@ -0,0 +1,90 @@
+# Blender v2.82 (sub 7) OBJ File: 'mis_grad.blend'
+# www.blender.org
+o plates_bottom_plate4
+v 3.125000 -3.996151 4.066700
+v 3.125000 -3.820690 3.082209
+v -3.125000 -3.820690 3.082209
+v -3.125000 -3.996151 4.066700
+v 3.125000 -3.968363 3.055890
+v -3.125000 -3.968363 3.055890
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+v -3.125000 -3.433780 1.745639
+v -3.125000 -3.730960 2.700459
+v 3.125000 -3.577003 1.701062
+v -3.125000 -3.577003 1.701062
+v 3.125000 -3.874184 2.655882
+v -3.125000 -3.874184 2.655882
+vn 0.0000 -0.9845 -0.1755
+vn 0.0000 -0.1755 0.9845
+vn 1.0000 0.0000 0.0000
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+vn 0.0000 -0.9548 -0.2972
+vn 0.0000 -0.2972 0.9548
+vn 0.0000 0.2972 -0.9548
+s off
+f 7//1 6//1 5//1
+f 6//1 7//1 8//1
+f 8//2 1//2 4//2
+f 7//3 2//3 1//3
+f 3//4 8//4 4//4
+f 5//5 3//5 2//5
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