Tag: perspective
architecture – What does it mean from a theoretical perspective when an architectural style is proven wrong?
There is a vivid discussion about the question whether the MSA is an architectural style at all. There is even evidence that it is formally not an architectural style.
Just a short question: What would it mean theoretically? I guess the chain reaction would be rather small.
Other opinons? First starting points? I’m curious what you think.
If you want to do a short deep dive I suggest this page here: https://ozimmer.ch/patterns/2020/07/06/MicroservicePositions.html & dig deeper in the sources
3d – Perspective of a Point Light
I’m trying to calculate shadows by projecting the silhouette of each object seen by the light source.
(The shadows are just going to go on planes.)
To get each silhouette I take a snapshot from the point of view of the light source looking at the object.
But I’m confused what the field of view of the snapshots is analogous to in the real world.
I was thinking perhaps the size of the light source?
But there’s both horizontal and vertical field of view, snapshots in all directions, and I’m lost.
So I’m asking what dictates the perspective of these snapshots.
algebra precalculus – I have seen “Thunderbirds”. One mile away – 1/4″ long from my perspective. How big were they actually?
How big is an object actually – if I am a mile away from it and it appears to be 1/4 ” in length ?
I am standing outside looking up at a 45 degree angle towards a huge wall of storm clouds that are a mile away. Ahead of these clouds is a flock of birds that are 1/4 ” in length. These were what I believe were the fabled “THUNDERBIRDS”. I am 64 years old, have lived on an air force base for 20 of those years, and the last 35 – near an airport. These objects were not planes, and were not in the airports flight path, but they appeared to be the size of a 747. They were huge and flying side by side @ twice their size apart.
The Indians say the thunderbirds fly ahead of storms – which is what they were doing. I am now a believer. How big were they ?
Understanding the math behind perspective matrix in OpenGL
I’ve been trying to figure out the math behind perspective matrix for 2 weeks now but I’m failing badly. I understand the theory behind the perspective matrix but I am not sure how the math works.
The code:
def perspective(fov: Float, aspect: Float, zNear: Float, zFar: Float) = {
val h = Math.tan(fov * 0.5f).toFloat
val c00 = 1.0f / (h * aspect)
val c11 = 1.0f / h
val c22 = (zFar + zNear) / (zNear  zFar)
val c23 = (zFar + zFar) * zNear / (zNear  zFar)
Matrix4(
c00, 0, 0, 0,
0, c11, 0, 0,
0, 0, c22, c23,
0, 0, 1, 0
)
}
What I understand
I’ve seen video tutorials by Jorge Rodriguez & Arpan Pathak but I cannot fully relate it to the perspective matrix in the function above.

Congruent triangles: Following Arpan’s video I understand that to project a point P=(x, y, z) onto the a 2D
XY
plane I need to create a frustum and which is then used to find it’s projection P^{‘}=(x^{‘}, y^{‘}, z^{‘}) using congruent triangles relationship. Arpan’s video and the final matrix makes sense but I do not see how it relates to the perspective function above? Here is my attempt. 
Following the above I switched the frustum in opposite direction to see how it would apply in OpenGL using the perspective function above with
zFar
andzNear
parameters but it’s no way close to the perspective matrix in the code.
Unreal Engine 4 Post Processing material isnt working on different viewports except perspective
I would like to render a silhouette of models, I found stencil would be the best way to capture. But when I am working with stencil postprocess material its does not work with other viewports except perspective. Post fx material already enabled in the different view modes.
How to make a custom 3d view cone that mixes orthographic and perspective cameras
I’m trying to make a camera that displays objects the same height no matter the distance, but still changes width relative to distance. Similar to having an orthographic view vertically and a perspective view horizontally. From what I’ve gathered the best way to go about this is to create a custom 3d mesh. Is that correct or is there a more efficient way? Thanks!
photo editing – Why doesn’t my Gimp perspective transform apply to the entire image?
You say:
When I select the Perspective tool and click anywhere in the canvas, the grid appears, already scaled to just the subject
Emphasis added, because that’s important. This is not the normal behavior of the perspective tool. Normally, if you just click, the grid will cover the entire image. It sounds like you have your subject preselected. You don’t describe having done that (and I don’t see the “ants” in your screenshots), but perhaps you have “show selection” off (ctrlt
), and previously selected the subject area and forgot it.
The behavior when working with a selection of part of the image is exactly what you describe.
Photoshop 22.3: Change photo perspective
I’ve stitched together a few screenshots using google street view and now I want to change the perspective of the photo.
It’s current view is from the street, I want to change the view as though your looking down from a higher level.
Current view as below
The view I want to change to using perspective warp is as below.
Is this possible using perspective warp on photshop, if so, how do I do that. Thanks in advance.
unity – How can I set perspective camera in portrait to fit screen sizes
I want to fit a perspective camera in different mobile portrait resolutions to see always the same objects in screen.
Doing a research about my problem I have found this post Scale camera to fit screen size unity that have a similar problem than mine, but he ask for an ortographic camera also horizontal.
My problem is the same but in perspective and vertical, I have tryed to adapt the solution code to my project but I don’t know why isn’t working, can someone explain to me the code or helpme to understand the maths behind them so I can figure how to do it?
My code for vertical
public float VerticalFoV = 60.0f;
// ...
void Update() {
float halfHeight = Mathf.Tan(0.5f * VerticalFoV * Mathf.Deg2Rad);
float halfWidth = halfHeight * Screen.width/ Screen.height;
float horizontalFoV = 2.0f * Mathf.Atan(halfWidth) * Mathf.Rad2Deg;
Camera.main.fieldOfView = horizontalFoV;
}
Sample code for horizontal
public float horizontalFoV = 90.0f;
// ...
void Update() {
float halfWidth = Mathf.Tan(0.5f * horizontalFoV * Mathf.Deg2Rad);
float halfHeight = halfWidth * Screen.height / Screen.width;
float verticalFoV = 2.0f * Mathf.Atan(halfHeight) * Mathf.Rad2Deg;
camera.fieldOfView = verticalFoV;
}