Questions tagged [projections]
Questions about the conversions of a 3D model to a 2D model.
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Ocean screen grid projection and animation
I am trying to port the Bruneton Ocean demo to Vulkan and I am having a bit of trouble with the coordinate system. I am using the matrices from the original code but I am not sure what this is doing:
<...
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Name of non-standard perspective projection where parallel lines do not meet at a single vanishing point
I have made a non-standard perspective projection for a rectangular room (see left figure), in which for stylistic reasons, I chose to make the perspective "width" of the walls equal ...
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How are these two projection matrices related?
I have two 3D perspective projection matrices $A,B$ with standard projection parameters $k=\cot(\theta/2)$, where $\theta$ is the field of view, $n$ is the $z$-near value, $f$ is the $z$-far value, ...
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In perspective projection matrices, why isn't $z_\text{eye}$ mapped linearly to NDC?
As far as my understanding goes, in projection matrices $x_\text{eye}$ and $y_\text{eye}$ are mapped linearly to NDC by first using proportions to find $x_n = \frac{n\cdot x_e}{-z_e}$ and $y_n = \frac{...
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Determine horizontal FOV of a panoramic photo
Say I have a panoramic photo (less than 360) and would like to view it in a cylindrical screen in a VR headset to get an immersive experience. How to determine the optimal width and height of the ...
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Formula for cubemap resolution for intended equirectangular resolution
Suppose I want to render out 6 cubemap cameras (90 degree FOV etc.) with the intention of combining them together in post-production into an equirectangular (latlong, 2:1) image.
Suppose I also know ...
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How to extract points corresponding to faces from cube map projection (CMP) of panorama from point cloud data
I am working with the standford2d3d dataset http://buildingparser.stanford.edu/dataset.html which contains panoramas of various scenes and a .mat file of the point cloud information of all the scenes. ...
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viewing direction vectors are not parallel in orthographic projection
I did some math with orthographic projection matrix to compute viewing direction vectors in screen space.
I thought all viewing direction vectors should be parallel in orthographic projection because, ...
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Object appears in unintended parts of the screen when using manual WorldToScreenPoint
Hy guys I'm new to 3d graphics and i lack some Linear algebra knowledge. I tried to recreate Unity's worldToScreenPoint method with kotlin on android. I copied some code from their forum and wrote ...
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3D engine projection distortions
I'm trying to write my own 3D engine using Python and Pygame.
I have successfully implemented rotation and projection matrices to display 3D models. However I am so far unable to implement translation ...
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Is it possible to render to a octahedron texture directly?
I am considering using octahedron textures for environment mapping, opposed to sphere or cube mapping due to their low memory footprint and the quality they result in.
Is there a possibility to render ...
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What are applications of 3D geometry to 2D geometry projection and occlusion handling?
As a layperson in the field of computer graphics, I rarely see practical applications of algorithms that take 3D geometry as the input (along with some camera and lighting parameters) and output the ...
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My projection matrix for OpenGL fails on non-symmetric boundaries
Assuming my viewing volume has x coordinates varies from l to r, and y varies from top to bottom, and finally z-axis varies n to f, I derived the following projection matrix:
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How do I evenly subdivide the projection of a circle in 3D?
I want to draw a circle in 3D from line segments. There are plenty of examples how to do this with an even number of subdivisions in 3D space, but I want the minimum number of subdivisions to produce ...
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Clever projection of point onto triangle?
I know of at leas tone way to project a point onto a triangle.
Project onto the plane, check barycentric coordinates, if outisde triangle, project onto the 3 segments, check distance, retain closest ...
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