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Questions tagged [volume-rendering]

In the case of Direct Volume Rendering (DVR), a transfer function (TF) maps the raw volume data to optical properties needed for image synthesis, e.g. from opaque black and white images to translucent and coloured results.

In the case of indirect rendering methods, opaque surfaces get extracted by preprocessing the raw volume data, e.g. resulting in isosurfaces.

105 questions
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Fast interpolation of regularly sampled 3D data with different intervals in x,y, and z

I have some volumetric imaging data consisting of values sampled on a regular grid in x,y,z, but with a non-cubic voxel shape (the space between adjacent points in z is greater than in x,y). I would eventually like to be able to interpolate the…
ali_m
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volume rendering (using glsl) with ray casting algorithm

I am learning volume rendering using ray casting algorithm. I have found a good demo and tuturial in here. but the problem is that I have a ATI graphic card instead of nVidia which make me can't using the cg shader in the demo, so I want to change…
toolchainX
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How could I polygonise a bool[,,]

If anyone cares, I'm using WPF.... Beginning of story: I got a series of gray-scale images(slices of a model). The user inputs a "range" of gray-scale values to build a 3D model upon. Thus I created a 3D bool array to make it easier to build the 3D…
None
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How to visualize 3D scalar field with Helix.SharpDX Volume Rendering?

I have a task to visualize 3D field of scalars using Helix Toolkit. The input array contains double values without limitations, but usually somewhere between [-50000, +50000]. The scalar value affect a color of a cube: The minimum value have a blue…
Aleksei Petrov
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Matlab 3d volume visualization and 3d overlay

The question is pretty much the title. I have a 3d volume loaded as raw data [256, 256, 256] = size(A). It contains only values of zero's and ones, where the 1's represent the structure and 0's the "air". I want to visualize the structure in MATLAB…
scigor
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PCA on a 3D image to obtain 3 principal axes

I have an anatomical volume image (B), which is an indexed image i,j,k: B(1,1,1)=0 %for example. The file contains only 0s and 1s. I can visualize it correctly with isosurface: isosurface(B); I would like to cut the volume at some coordinate in j…
gari
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Matlab's slice() function not working as desired

I want to plot discrete 2D images at 13 z locations at [4:4:52] using the following lines of code. a=100; [mesh.x,mesh.y,mesh.z] =…
user238469
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1 answer

C- Indexing x,y,z coordinates in a 1D byte array

I want to evaluate the values of the surface to implement a marching tetrahedron algorithm, but I don't understand how to work with .raw unformatted data. After loading a .raw file with a volume dataset into a 1D byte array, what arithmetic…
andandandand
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Rendering a surface (or a smoothed volume) from a numpy array with VTK

I'm discovering VTK and want to use it to plot a 3D numpy array. So far, I've managed to convert a numpy array to a vtk.Volume and displaying it but from there I am having a hard time getting something pretty. I get a very blocky rendering like this…
Soltius
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Load non power of two image stack into 3d texture OpenGL C++

i have tried to load stack of .png image files into glTexImage3D for volume rendering purpose. However, i just cant make it work as it keeps crashing. BTW, the problem seems to be related with pData. Below is the code for your reference: GLubyte *…
vincent911001
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VTK - explain simple code

Can you explain me following simple code ? VolumeScalarOpacity->AddPoint(0.0, 0.0); VolumeScalarOpacity->AddPoint(0.25, 0.0); VolumeScalarOpacity->AddPoint(1.0, 0.1); and VolumeGradientOpacity->AddPoint(0.0,…
Flaviu_
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Computing the gradient in volume ray casting

Please help me clear up this question I have about the volume ray casting algorithm: In the wikipedia article (link), it says that "For each sampling point, a gradient of illumination values is computed. These represent the orientation of local…
Imre Kerr
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Texture is not generated valid (probably)

My app for volume ray casting in WebGL is almost done. But i have found a problem. I have to simulate 3D texture by 2D texture. It is not problem. I am creating a huge texture from small slices. Dimensions of huge texture are about 4096x4096px.…
Xrew
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How can I get view direction from the OpenGL ModelView Matrix?

I am writing a volume render program that constantly adjusts some plane geometry so it always faces the camera. The plane geometry rotates whenever the camera rotates in order to appear as if it doesn't move--relative to everything else in the…
AAB
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Processing large image volumes

I have a huge 3D volume, which sizes above 2GB. I want to load this data, process it and display in my application as a 3D volume, in which zooming and rotation of volume cn be performed. I saw applications which loads this huge data and displays…
rps
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