Real Artifacts

	When your octtree acceleration data structure gets displayed instead of the polygons, or, a modern art installation in Portland Oregon from 2015. (thanks, Adam Sawicki).
	Anime art, or cartoon decoration for a new restaurant in NYC, a recurring theme. Source
	Y axis flip problem, or part of a project called "The World Upside Down." Source
	NPR image, or the result of a winter storm. Source and more
	Up axis translation bug, or a particularly short car. Source
	Semitransparency applied to the blade, or a well-aligned reflection. Source
	Sometimes only half the model loads. Source
	Undersampled motion blur, or a picture of some mugs in a store. This one hurts my eyes to look at it. Source thanks to Pete Shirley
	Voxelization bug, or a sculpture by Han Hsu-Tung. Source
	It's frustrating when you lose a triangle in your mesh; having backface culling cause the interior to disappear just calls more attention to the problem. Source
	Low quality shadow filtering (via Morgan McGuire's RT). Source. Similar sampling problems here.
	Lights only render, materials unassigned (thanks, Moritz Weller). Source, third picture in series.
	Procedural modeling bug (via Pete Shirley). Source
	When scale factors go awry (found on reddit's r/confusing_perspective). Source
	Uninitialized data in a render target texture after rendering all 3D objects but before rendering the skybox (thanks, Adam Sawicki). Source
	To quote Stefan Werner, "Subtract 0.5 from the displacement map," or an artwork by Erwin Wurm. Source
	Box mapping (thanks, Pierre-Félix Breton). Source
	Y translation problem, or she's behind a ground-level wall (thanks, Ryan Haines). Source
	Only had enough memory for five different textures [click image to see the full-sized photo for the effect] (thanks, Kienan A.).
	Bad vertical positioning of a trash bin in a scene, or a wet spot in front of it. Source
	It's not uncommon to accidentally apply the same texture and shader to all surfaces (thanks, Pierre-Félix Breton). Source
	When you can only afford a 10x10 shadow map (courtesy of Mauricio Vives).
	Environment mapping on a simple test object, or the Cloud Gate sculpture in Chicago. Source
	Bug in the interpolation of samples in a shadow map, or arrays of LED lights? The title of this work is "My country is so poor it even has low quality shadows." Source
	Multiple textures put in the same image to avoid texture switching, or a single photo. Many other nicely-aligned photos here. Source
	Extreme Peter-Panning of shadows, or Lake Charlevoix in Michigan has the clearest ice you will ever see. Source
	Odd bump mapping, or entirely flat farmland in eastern Colorado with wind-blown and melted patches of snow. Source
	NPR and realistic shading combined, or a cafe in Seoul. Source. And, see a more elaborate version in Sydney, Australia.
	Some horizontal offset problem or clipping plane bug, or the sliced footwear art of Sakir Gokcebag. Source
	Test scenes for area light source reflections, or Reuben Wu's work done with a moving drone equipped with a lighting rig. Source
	Refraction? Check. Depth of field? Got it. Caustics? Looking good. Specular reflection off of glass material? TODO... Source
	In Montreal, that building in the middle appears to have the front faces culled out (courtesy of Mauricio Vives). Another view to make sense of it.
	Lights shining on 50 disco balls makes the scene look like an undersampled ray trace. Source
	A debugging view showing the surfaces without textures applied. Or forced perspective. Source
	A tower at Google in San Francisco had its material set to be semi-transparent. Or the Napa fires around 10/10/2017 caused a haze in front of the building, illuminated by the sun (thanks, Paul Debevec; Facebook if you are friends).
	This church in Borgloon, Belgium, has a rendering bug. Source
	This image of the restaurant at LAX looks like it is a debug visualization for an acceleration data structure (thanks, David Larsson). Source
	Objects are made to look as if they were deleted using an image manipulation program. Source
	Artist Julien Attiogbe covered a building with distorted photos of itself. Source
	Edoardo Tresoldi's pavillion make of wire - a true wire-frame construction. Source
	A temple covered in ash from the Ontake volcanic eruption, Japan. From a large collection of unusual photos, it's the fourth one down. Source
	When the sun is directly overhead in Hawaii, it looks like a bad video game render. Source
	The world's blackest material looks like a bug (thanks, Pierre-Félix Breton). It is also part of an art world tiff. Source
	The 'Still File' project made this scene to look like a classic Whitted ray trace. See the three other images, and how they did it. Source
original gallery, 2016 on back
	That was not the color of caustic that I expected. Source
	The studio-level lighting, exotic costume, short hair, and plasticy skin (from makeup) conspire to make this cosplayer read as a high-quality CG render. Source
	These clouds just look wrong!
	A thin layer of water on a salt lake creates a mirrored surface that looks like an overly glossy desert sand BRDF. Source
	This car's mirror surface looks like the material artist got too carried away with chrome. Source
	Color bleeding? Wireframe? Ambient occlusion? This looks like a beautiful radiosity test. Source
	These interleaved post-it notes create an effect that resembles z-fighting (thanks, Tomasz). Source
	The focused crepuscular rays through the atmosphere created by reflection from that building look fake.
	This carpet's pattern resembles incorrectly assigned texture coordinates or a bug in a projection matrix computation.
	A real, 3D shoulder bag designed in a style that looks like hand-drawn animation.
	A colored glossy reflection creates an unexpected red wall paper pattern (thanks, Pete). Source
	Peter Shirley took this photograph in which the glossy highlight on the metal building appears to be too bright and in the wrong place because it is brushed metal (better check your surface normals, Pete!).
	Adam Sawicki sends this real life shadow that looks like the aliasing artifacts from low-resolution PCF shadow maps. Source
	Padraic Hennessey sends these peeled potatoes, which look like they have been ray marched with too few iterations.
	The reflections in the lake look like undersampled stochastic reflections. From Aras Pranckevičius' blog. Source
	Tomás saraceno's net installations look like Photoshop disasters when photographed. Source
	This kind of boosted-saturation color bleeding usually only happens in CG. Source
	Here's that path tracer reflection test that you rendered (Thanks, Eric). Source
	A snowy scene looks a lot like an ambient occlusion-only rendering (Thanks, Mauricio).
	Eric Haines needs better shadow-map biasing, since he's getting single-texel light leaks. Or maybe there are tiny holes in his window blinds.
	The camera is exactly at the height of a former flood line, making the picture look like there was a bit error leading to incorrect decoding of the lower scan lines. From The Line by Palindromo Meszaros (Thanks, Eric). Source
	The water is so clear that it looks like the shadow-map bias was cranked up too high (Thanks, Tomasz "Dab" Dąbrowski).
	Camel thorn trees against an orange dune at sunrise look like a painting (Thanks, Aaron Size). Source
	Aliased shadows look like bad shadow map filtering; taken in the stands of a baseball stadium. (Thanks, Padraic Hennessy).
	Basalt pillars look like some sort of modeling error, or hexagonal voxels. Source
	Real-world interpenetration (Thanks, Adam). Source
	Strobing lights create the appearance of temporal undersampling artifacts on the blurred snow. Source
	Federico Diaz's sculpture at MoCA. This image is a visualization; the real sculpture is also made of voxels but has a different shape. (Thanks, Adam). Source
	Justin Harder's voxel motorbike (Thanks, Adam). Source
	Horizontally scrambled sculpture: forgot your end of row padding again? (Thanks, Eric). Source
	Giant 30-story sinkhole in Guatemala is so perfectly cylindrical that it looks artificial. Source
	Real animated 3D sculpture that looks like a rendered wireframe teapot (Thanks, Spike). Source
	The tree in the midground looks like the Stanford Bunny, a common rendering test object (Thanks, Adam Sawicki). Source
	Looks like radiosity---a fact that was not lost on Cindy Goral. Click through to the comparable image from her seminal thesis. Source
	Voxel/oct-tree car--check out the shadow (thanks Eric Haines). Source
	Floating man optical illusion / bad shadow map bias (thanks Eric Haines and Pete Shirley). Source
	NPR female model (thanks Eric Haines). Source
	Synthetic-looking real house (thanks David Luebke).
	Hard stenciled shadows in the desert again (thanks Eric). Source
	"Undersampled" shadows in Pete Shirley's living room due to his window blinds.
	"L-System Plant" by Adam Sawicki (who notes it's called Rhipsalis, in case you want to get one).
	"Percentage Closer Filtering" by Adam Sawicki.
	Eric Testroete's "Low Poly Head". Source
	"Voronoi Diagram Model" by Adam Sawicki (although my colleague Frank Morgan would tell you that bubbles are not Voronoi!).
	Benedict Radcliffe's wireframe car.
	Sara Watson's "invisible car" (from DailyMail).
	"Undersampled" shadows in the Seattle Public Library's Faye G. Allen Children's Center. Source