You can't? I'm pretty sure you can do this on Matlab! It was made for matrix operations! :D

You might be able with the movie function but Matlab is too clunky for this, once you get the sphere, you can get an STL and export it to other better software (like Blender)

If you are going to change the number of points, then uPTS and wPTS should be updated, instead of 3 (like in the video) write 5. And also, the arrays x, y, z in the video are 3x3 (or uPTS x wPTS) this means that in your case they should be 5x5 arrays. 4:15

@@prot0form775 Thank you ! I made it. The task for me here is to make an animation of different Bezier surfaces. Do you have any idea how to make it, please ? Thank you!

It is possible but making a video of with right now is impossible for me, so I will try to explain it here following what is done in the video for a normal cone: The cone is divided into a number of cross-sectional planes which are basically all circles of different radii, and they are arranged equally along the axis. Let's assume the axis is the X direction, and the circular cross sections lie on the Y and Z directions. And let's assume that the origin is at the base of the cone. This means that the offset will be in the Z or Y direction (or both!), and the process to achieve this is by translating each circular cross-section by a specific amount. In other words, adding a value to the Y or Z values for every cross section. So what you have to do, is create a vector of length [1, nCS] and each having the distance of this displacement for every cross section and then add it to Z or Y arrays.

Thanks, thats helpful! @@prot0form775

In python you can define functions in another ".py" file (here it was utilities.py) and can use the defined functions in any other python file by importing the functions using the format "from [filename] import [function]". If you want to import all the functions at once, you can import all the functions with a single line of code using "*" instead of specifying the name of just one function name. e.g. from [filename] import * In the video he uses "from utilities import *". Where "utilities" is the file name and "*" tells python to import all functions. Near the end of the video 9:01 he even opens the file "utilites.py" where he has defined some functions beforehand.

thank you@@waqqiali2960 !!!

I am sorry for the late reply, you might have already found the answer, but for posterity: the utilities library is a library I created to store the functions of the code, you can do that too by creating a .py file and saving your functions there. The .py file must be in the directory of the main script.

This should work for all continuous objects as long as you can assemble the node matrices. That is the main challenge.

:D

I'm pretty sure you can do this with other logic, but the main reason we create that matrix with 0 values first is because in the for loop, you have: xbezier = xbezier + something. You need xbezier to be declared beforehand. The reason we populate it with zeros, is that since we are adding stuff to xbezier every loop, an initial value of 0 will not change anything. If we were multiplying, we would use 1s instead. Hope this helps.

Ya, by the way thank u for video, I was trying to hard code for b spline after coding all intervals ,I was not able to get or understand that basis function for different values of u.. How and what...... Please I beg u do a video on B spline hard code in python.. Because I am m tech student. I want doing projects on IGA SO I need to do it... And if have any video or materials of calculation of b spline do suggest.

@vasanthkumarkallannavar7594 I'm preparing a series of videos for B-splines, but is a tough concept to grasp, so as soon as I get it working I'll post it.

I used Premier Pro for the video and the equation writer in Word for the equations.

That could be a number of things. In what line is this error happening?

That is a very useful and detailed advice for the future. Thank you so much!

Thank you very much! I am a graduate in the hypersonics field, mainly numerical and analytical. My work is only tangentially related to computer graphics. Sadly I cannot share my work.

as far as I know, you can't.

Hi! one question, what software are you using to open the created stl file? The NaNs are probably from the normals. Some apps don't even read them but if they do, that problem might occur. A workaround is to replace all NaNs with 0. Like isNAN(unit_normal) = 0

@@prot0form775 The matlab built in function shown in my post. I did change the NaNs to 0 0 0 and that did fix it. All is good after the 0's replaced NaNs. Thanks

in lines 6, 7, and 8 you specify the coordinates of these points, and the number of points have to match with the number you specified in line 3 for the number of control points. If you want 4 control points, change that 3 for a 4.