How do I Improve Graphics Performance in Matlab?

I made a 3D chess set in CATIA, converted it to VRML format (.wrl), and will use it with an AI, GUI, etc. as part of a chess program. When converting to wrl, I cut down on the file size as much as CATIA would let me, so all circular objects are octagonal. The total file size of the board and the pieces is around 2MB. I incorporated a click and drag feature on the pieces, but for whatever reason, Matlab struggles mightily to render the chess set while moving the pieces. Movement is extremely choppy and rotating the set takes forever, even with navigation style set to "fast." However, when I used a web viewer for VRML objects, rendering the chess set was child's play for the web viewer. Movement was smooth, frame rates were high, etc. But not so when viewing it in Matlab. CPU usage (using Task Manager) was at around 30-50% when I moved a piece around. That's unacceptably high. The computer specs are: Dell Precision series, nVidia graphics, xeon processor, 4GB ram.

Anyway, why is this? I looked around on Mathworks for a possible cause, but no luck. I would appreciate any help, as this project is due in a few days. I tried everything, but to no effect.

Answer 1

[Jan]

Which Matlab version are you using? Which renderer is active? And if it is OpenGL, do you use the hardware or software rendering? How do you move and rotate the objects?

I do not have problems to display 21 spheres of 10*10 facettes and 25 cyclinders, a checkerboard floor and some 2D stuff with the hardware OpenGL renderer. This GIF is recorded with about half real-time on a PentiumM 1.5GHz, 512MB, a 16MB graphics card (a T40 IBM laptop), Matlab 2009a:

I can add further objects without reducing the fluently appearence. surface objects are drawn faster than patch objects. Therefore I assume your slow displaying is a problem of the VRML viewer in Matlab. Can you convert the objects to surface objects?

[chris]

Matlab r2011a, I move the objects just by clicking on it it and dragging it. I don't know how I would see which thing is running when rendering. I alsobfont know how to convert to surface objects

[Jan]

Without seeing the code we cannot know what's going on also.

[chris]

I made a vrml file of the chess set, with planesensors in it. The code for the whole set is around 20,000 lines. I open the set by double clicking on the file in the directory. i don't mess with any settings or anything.

[chris]

I'm pretty sure the computer is not taking advantage of hardware acceleration or whatever, because the web view does (directx or opengl), and it is loads faster. I just need to know how to set it so Matlab tells itself to use hardware acceleration instead of simply relying on just the CPU.

[chris]

And what code should I post? I don't run any code to open the file. I could post the vrml code, but that's 20,000 lines.

Answer 2

[chris]

Does anybody else have an idea of how to fix this? Its quite urgent.

[Daniel Shub]

First: http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

Second, you have not given us much to go on. You haven't given us a MWE from which we can try and help you. See: http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Jan]

If the web-renderer works fine, use it. If Matlab is slow when displaying the VRML objects, convert them to another format.

[chris]

Its urgent because it is a large facet of my group's college term project.

The web renderer doesn't 'connect' with matlab at all. Sure, it opens from matlab, but i can't interact at all with it from matlab. That makes the web renderer completely useless. So I have to settle with the crappy, slow, Simulink 3D animation internal viewer that for whatever reason uses software rendering instead of hardware rendering.

There is no code I could post other than the 20,000 line VRML file code itself. And the problem isn't the VRML file, its the rendering.

And I can't not use VRML. the VRML format allows me to use transform nodes and planesensor nodes, which lets us click on a piece and move it, or move it from matlab code. Unless there is another file format that allows us to do this, its not an option.

What else should I post? I just need to find a way for matlab to take advantage of the computer's hardware acceleration. I've tried everything of what little i could bring up on the internet: nothing on this page worked http://www.mathworks.com/help/techdoc/ref/opengl.html either.

[Daniel Shub]

@Chris, clearly you didn't read either of the links I provided. As Walter says "This is not a resource for HELP NEEDED URGENTLY. If you need help urgently, then you should be hiring a consultant, such as http://www.mathworks.com/services/consulting/"

I highly doubt that we need such a complicated VRML file to see the problem in the rendering. YOU need to spend the time to create an example that we can follow. Then you need to tell us what you see/get and what you expect to see/get. Without that it is highly unlikely that we can help you.

[chris]

I read the links. However, because this project is due in 2 days, it's a very urgent issue. And I can't afford to hire someone, because I'm a college student with hardly any money.

All I'm trying to do with the vrml file is to open it up and expect the viewer to perform like a normal vrml viewer. but what I see is a slow, jerky vrml renderer. An example to witness this effect would simply be opening a file bigger than 2MB in Matlab and trying to rotate it. Then open the same file in a normal vrml viewer and seeing that it rotates the model like it's nothing. I'm certain it is a software render vs. hardware render issue. That is all. I didn't think it was a complicated issue.

[Jan]

Chris, please read the links again. And if they are still not clear, read them again. Walter is a very experienced programmer. This does not only mean, that he can use the correct syntax, but this requires a deeper knowledge of the physical background and efficient application of project management tools. Participants of this forum can profit from Walter's knowledge for free! If he tells you, that your problem is not urgent, it is worth to think as long about this opinion until you get his point.

Answer 3

[Jan]

Although you repeatedly claim, that your project is urgent, you needed 3 days to tell us, that you use the "Simulink 3D animation internal viewer" to display the VRML file. Instead of this important detail, you explained details about your work with CATIA - a software or language I do not know and as far as I understand it is not relevant for the problem.

You said that 30-50% cpu load during moving a piece around is unacceptable high. Why? I would accept 100% or is a partially sleeping cpu important for your project? If so, why?

But let me summarize the already mentioned facts:

1. You are using the Simulink 3D animation internal viewer to display a not really large VRML scene.
2. You are not satisfied with the performance.
3. Neither you nor another user of this forum knows a magic switch, which makes the viewer 3 or 4 or what ever times faster - btw, you did not specify which amount of acceleration is wanted.

Then this conclusion is obvious: The Simulink 3D animation internal viewer is not sufficient for your project. This is not a fault of Matlab, you simply had wrong expectations and did not test this early enough.

I see two solutions:

• Either use another tool for displaying. I have explained, that Matlab can display surface objects with a sufficient speed for user interactions in 3D. I do not think that this can be programmed in 2 days.
• Face the facts and finish the project with an unfinished visualization. This would not be the first project, which is not ready in time. All professional programmers have experiences with a failing project management.

I hope and think, that you have learned a lot from this project. Therefore I'm still convinced, that your problem is not "urgent". Wearing burning socks is an urgent problem. I have the impression, that you simply did not start to solve the problem early enough. Then repeating the project next term or year with more experiences is a valuable solution.

And for questions in this forum, other forums or scientific discussion, I repeat the suggestion to read and consider http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer . A good question is succinct and requires no guessing for the answering.

Good luck!

Answer 4

[timo]

Now in November 2015... I have exactly the same issue with Matlab 2015b Windows 10, GTX 770... Ps: before telling me i use a complicated model, i just ran "vrmemb" command

Matworks please fix the internal 3d rendered in Matlab. Its unusable

[Jan]

Please provide any details of your problem. The OP did not specifiy the problem exactly enough.