23 votes
Accepted

Why do we have graphics frameworks like OpenGL and DirectX, when games could just draw pixels directly?

Speed is the most common reason why this is not done. In fact you can do what you propose, if you make your own operating system, its just going to be very slow for architectural reasons. So the ...
joojaa's user avatar
  • 8,437
14 votes

How is Anti Aliasing Implemented in Ray Tracing?

Raxvan is completely right that "traditional" anti aliasing techniques will work in raytracing, including those that use information such as depth to do antialiasing. You could even do temporal anti ...
Alan Wolfe's user avatar
  • 7,801
14 votes

Why do we have graphics frameworks like OpenGL and DirectX, when games could just draw pixels directly?

work on any 32-bit color GPU (even old ones)? Bit of history here: this is how games were done on PC up until graphical accelerators started to become available in the mid-90s. It did indeed work on ...
pjc50's user avatar
  • 241
14 votes

Why do we have graphics frameworks like OpenGL and DirectX, when games could just draw pixels directly?

Just to add to joojaa's answer, things are still being drawn pixel by pixel. You're just generating the pixels using a vertex shader/assembler/rasterizer, then texturing and lighting them using a ...
russ's user avatar
  • 2,392
13 votes
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How is Anti Aliasing Implemented in Ray Tracing?

I think it's safe to say that there are two different ways of doing AA in raytracing: 1: if you have the final image and the depth image it is possible to apply almost all existing techniques that ...
Raxvan's user avatar
  • 253
7 votes

How is Anti Aliasing Implemented in Ray Tracing?

Let's suppose a fairly typical raytracing main loop: ...
Julien Guertault's user avatar
7 votes

Is there a image-format that support an array per pixel?

OpenEXR might be a good fit. You can have an arbitrary number of channels per pixel and the data types for each channel can be integers. http://www.openexr.com/
Daniel Gollás's user avatar
5 votes

Difference in pixels between different monitors' sizes

The answer to both your questions is the same: the physical size of the monitor makes no difference at all. If your screen is 1920x1080 pixels, and you display a 960x540 image without any scaling, the ...
Dan Hulme's user avatar
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4 votes
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Do we ever consider the size of the pixel to calculate the color in Ray Tracing?

Yes, and there are several ways this can apply. First off though, we need to fix a misconception in your diagram. Even if pixels really were square, the volume contributing to the pixel gets wider as ...
Dan Hulme's user avatar
  • 6,810
4 votes
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What is a scaling factor of the screen?

What they're saying is you don't have to render the game at the same resolution that it's displayed. For example you could be in a display mode of 1920×1080, but have the game rendering at only 1280×...
Nathan Reed's user avatar
4 votes

What is the optimal radius of gaussian distribution for determining pixel colour?

Imagine that one is rendering a picture of a flat floor with a uniform black and white checkerboard pattern that extends to the horizon; the checkers are large enough that they should be clearly ...
supercat's user avatar
  • 171
3 votes

Game texture looks pixelated at big distance

I think mip-mapping will help. This is the aliasing effect when the sampling frequency is lower than needed. When a large patch of texture projects only to one (or less than one) pixel, things like ...
Enigmatisms's user avatar
3 votes
Accepted

Why do some videos look smoother and others don't on the same monitor

As you have now mentionned that your computer can actually keep up (at 150 fps no less), I suspect you have a case of temporal aliasing. The problem is that 150 is not a multiple of 60. Let's say we ...
Olivier's user avatar
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3 votes
Accepted

Pixel packed texture source

The question is: is there a way to pass this type of texture to glTexImage2D as-is? Yes; you can just pass it as-is, but (looking at the docs) it is not supported directly. You'll need a custom ...
geometrian's user avatar
  • 1,980
3 votes
Accepted

Estimating real world object distance from photo

I may be misunderstanding what you're asking, but if you know the sensor size and the number of pixels in the object, then you can calculate the object size. For example, a Canon 7D has an APS-C ...
user1118321's user avatar
  • 3,411
3 votes

Estimating real world object distance from photo

Yes, theoretically, for the sphere no for other things in image. If it is possible to augment the situation then it is possible to measure anything you can track much more reliably. First, knowing the ...
joojaa's user avatar
  • 8,437
3 votes

Could a hexagonal pixel array store an image more efficiently?

If one examines old CRT television displays, one will observe red, green, and blue phosphor dots in a triangular lattice. Some LCD television sets had a somewhat similar arrangement; pixels were ...
supercat's user avatar
  • 171
3 votes
Accepted

human visual: relation of Distance and DPI

According to a review by Legge & Bigelow the arc or degrees of visual angle ($\alpha$) is, $$ \alpha = 57.3 \times S/D, $$ where S is height of object and D is distance to object. [1] $S/D$ is ...
joojaa's user avatar
  • 8,437
2 votes

Is there a image-format that support an array per pixel?

Probably .dds. You can store there textures array or 3d texture both can be use as array per pixel. You can try creating this textures with ...
Derag's user avatar
  • 596
2 votes

Difference in pixels between different monitors' sizes

Ad 1) Yes, if both monitors have the same resolution but different screen sizes, this means the pixels of the larger monitor are bigger. It could also mean the space between the pixels is different. ...
Paul Houx's user avatar
  • 140
2 votes

What is the name of this moving color pixels effect, for animating a painting?

This effect is called Color Cycling (or Palette Shifting). Mark Ferrari has a great GDC talk where he demonstrates and explains the entire technique. You can view a bunch of his artwork based on this ...
eclmist's user avatar
  • 222
2 votes
Accepted

How to use maximum resolution (pixel density) with OpenGL in MS Windows

You might need to use a setting to tell Windows that your program is DPI-aware, meaning that it can adjust to very high-resolution screens like many current-gen laptops have. Lots of older programs ...
Nathan Reed's user avatar
1 vote

Why do some videos look smoother and others don't on the same monitor

Humans don't really see anything beyond 20-25 fps. Even less is often sufficient; animation at 12 frames a second work quite well too. So when you watch TV, the fps of your image is 25-30, and yet ...
joojaa's user avatar
  • 8,437
1 vote
Accepted

Paint pixels on the image around the cursor for painting application

I don't know, why you consider your first approach hacky, but an alternative would be to analyze the shape of your brush and how it interacts with your underlying data structure. For example for your ...
wychmaster's user avatar
  • 1,251
1 vote

How is Anti Aliasing Implemented in Ray Tracing?

Just to add to the answers above: Distributed Ray Tracing (Cook, Porter, & Carpenter). Allows you to simultaneously do spatial AA, temporal AA (i.e. motion blur), and focus/depth of field. Best ...
Simon F's user avatar
  • 4,241

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