Contents
Is there a way to draw a sphere in OpenGL?
Many of the 3D tutorials for OpenGL are just on cubes. I have searched but most of the solutions to drawing a sphere are to use gluSphere (). There is also a site that has the code to drawing a sphere at this site but it doesn’t explain the math behind drawing the sphere.
How to generate a sphere in 3D NumPy array?
Given a 3D numpy array of shape (256, 256, 256), how would I make a solid sphere shape inside? The code below generates a series of increasing and decreasing circles but is diamond shaped when viewed in the two other dimensions.
Is the silhouette of a sphere the same from any angle?
One nice thing is that the silhouette of a sphere looks the same from any angle. However, if the sphere is not in the center of a perspective view, then it would appear perhaps more like an ellipse. You could work out the equations for this and put them in the fragment shading.
How to draw an n faced polyhedron in OpenGL?
A good way to generate an N-faced polyhedron where all vertices lay in the same sphere and all its faces have similar area/surface is starting with an icosahedron and the iteratively sub-dividing and normalizing its triangular faces (as suggested in the accepted answer). Dodecahedrons, for instance, are actually truncated icosahedrons.
How to draw a triangle mesh in OpenGL?
The following pseudocode generates a triangle mesh by evaluating a parametric function at regular intervals (this works for any parametric surface function, not just spheres).
How many triangles are in the icosphere in OpenGL?
Press the spacebar key to change the subdivision level. If the subdivision is 2, the icosphere consists of 320 triangles, and if the subdivision is 5, it has 20,480 triangles. Drawing an icosphere in OpenGL is identical to Sphere C++ class object.
How does the glusphere function draw a sphere?
The gluSphere function draws a sphere of the given radius centered around the origin. The sphere is subdivided around the z-axis into slices and along the z-axis into stacks (similar to lines of longitude and latitude).
What is the pseudocode for uresolution in OpenGL?
In the pseudocode below, UResolution is the number of grid points along the U axis (here, lines of longitude), and VResolution is the number of grid points along the V axis (here, lines of latitude)