Computer Graphics Stack Exchange
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1500 questions
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SSAO artefacts on iPhone (OpenGL ES)

I've never written shaders before, and now I'm trying to implement SSAO with SceneKit on OS X and iOS. I'm trying different SSAO shaders that I find, e.g. from Three.js, this one, and this one. On OS X they all work as they should, but on iPhone all…
pronvit
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Speeding up convergence: am I reinventing the wheel?

I'm trying to learn about raytracing by implementing things in Python 3. I know this is always going to be slower than something like C++, and I know the speed could also be improved by using GPU raytracing, but for this question I'm not looking for…
trichoplax is on Codidact now
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Why are inverse transformations applied to rays rather than forward transformations to objects?

When computing ray-object intersections against a transformed object, most raytracers apply the inverse transform to each ray and compute the intersection against a non-transformed object. Wouldn't applying the forward transform, putting the object…
Mark
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Volume Rendering in simple words

I am looking for a explanation about volume rendering in simple words, a step by step kind of, like ray tracing: for every pixel in the screen plane, trace a ray starting from the eye point to the screen pixel location, a compute the nearest…
arcollector
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HLSL Deferred Rendering

I've recently made the switch to Visual 2015 and the .fx files have been depreciated. My project contained .fx files for the shaders so I've been switching over. Only during the switch have I changed to using deferred rendering for lighting. The…
phatgreen
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Rotate image around its center

I'm struggling with a problem with image rotation. I'm using the idea of "Rotation by area mapping" in the following link: http://www.leptonica.com/rotation.html My c# codes are as follows. The idea is first to find the dimension of the rotated…
user2719
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Confused about z-axis behaviour

I'm a newcomer to OpenGL and I was playing around with drawing triangles with different z-coordinates. From what I understand, the z axis point out of the screen, and the -z axis points into the screen. When I draw a square with 3 corners at a 0.0…
Chara
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Rotate line around center

I have to use a propriertary graphics-engine for drawing a line. I can rotate the whole drawing by its origin point (P1). What I want, is to rotate it around its center point(M). So basically that it looks like the green line (L_correct instead of…
Tofferino
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What happens when you display a high resolution image on a low resolution screen?

For a non-computer graphics expert, what happens technically when you do this? Are multiple pixels merged to one to compensate for the lower resolution? And in how far will this affect the image quality? Would a high resolution image look sharper on…
AdHominem
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What is stereo about multi-view stereo?

What 3D scene reconstruction methods does the term "multi-view stereo" encompass? Is it only used for methods that apply binocular stereo algorithms (taking 2 views as input) in a pairwise manner? Or only methods based on disparity estimation? If…
tmlen
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Cannot use more than a couple of MB in a shader storage buffer

I am implementing a simple ray tracer with OpenGL. I have a shader storage buffer with all the triangles so I can test them for intersections in a compute shader. It works fine up to a certain buffer size. But if I have more than a certain amount,…
gartenriese
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OpenGL with SFML, create an n-pointed star?

Completely stuck on how to do this. Yes, it is a homework problem, but its the first we've had in the class so not too familiar with graphics. Also, seeing as its homework, please don't just give the answer, just some pointers in the right direction…
user2645
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implementing right handed coord system APIs on top of a left-handed rendering engine

I am trying to plug in a 3D game engine as the rendering engine for an existing graphic API system that uses a right-handed coordinate system. Game engines often uses a left handed coordinate system internally. So how can I convert the API…
atai
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OpenCL doesn't detect GPU

I installed AMD APP SDK and here my problem. The OpenCL samples do not detect the GPU. HelloWorld give me this: [thomas@Clemence:/opt/AMDAPP/samples/opencl/bin/x86_64]$ ./HelloWorld No GPU device available. Choose CPU as default device. input…
Thomas BRAUD
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Ray tracing - BRDF using Cornell measured spectral data

I wrote a ray tracer that implements various BRDF models (Oren Nayar, Lamber, Torrance Sparrow and so on). Now I'm trying to implement a BRDF from measured data. I choose the Cornell database data available…
Fabrizio Duroni
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