Good morning,

 

I have been attempting to run an annual glare simulation with DIVA and having some problems. After letting the simulation run overnight I returned this morning and the html report was open but with no image. The only files in the  results folders were the dgp and html files. Is there something I am missing here? I am only using the current perspective view and set up a calculation grid as prompted (which seemed like a current bug?). Thank you for any help!

 

-Steve

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Good morning Steve,

 

It sounds like something is going wrong with the DIVA-Python scripts on your computer which are responsible for generating the images.

 

We can test this by using a simpler (Climate-Based) simulation which uses a similar program to generate the images. To set this test up, do the following:

 

1. Click on Materials > Shading Controls.

2. Select "Conceptual Dynamic Shading."

3. Click Submit.

4. Click Metrics > Daylight Grid-Based > Climate Based.

5. Run the simulation making sure that "Show Daysim Report" is checked. I used an ambient bounce of 1 (-ab 1) to make the simulation go very quickly.

 

What I expect to see from this is a report html document which has some annual falsecolor plots showing occupancy and shading device status (see screenshot below). 

  

 

 

If you do NOT see this, it might be worth-while to re-run the DIVA installer, making sure that the Python programs all get properly installed at the end.

 

If you DO see it, then something went wrong in the DGP simulation somehow. In that case, please email me your .dgp file at alstan@jakubiec.net so I can take a look.

 

All the best,

Alstan 

 

 

Hi there,

I have the same problem as above and also when I run a point in time glare analysis just an image comes out with no any values (although I specify that I want to open it with the wxfalsecolor program. I would appreciate any help.

Thanks in advance,

Kostas

Hi Kostas,

The next version of DIVA will have its own installation of Python. This should prevent any image generation problems. If you follow the steps I outline above, do you get any image output?

also when I run a point in time glare analysis just an image comes out with no any values (although I specify that I want to open it with the wxfalsecolor program. 

The process which generates the image with the DGP evaluation in the top-left corner unfortunately ruins the physical data of the image, so we output it as a low-dynamic-range image and open it with the system default image viewer. You are right to suggest that the 'open with' option should not be present -- thanks for pointing that out! That said, the high-dynamic-range image is still available to be opened with c:\DIVA\Radiance\bin\wxfalsecolor.exe. You can fine the image in your .\[Rhino Filename] - Results\Daylight Images\ directory. 

Best regards,

Alstan

Hi Alstan,

Many thanks for your reply. Yes I followed the steps above but for example for the third graph I get a graph full in blue. However in the results folder and specificaly in the daylight images folder I get a dgp file. So I assume that everything is ok.

Now about the point in time glare image ( I am making use of the Gund_111 and I generate the interior view) something is going wrong. Please have a look in the image provided.

Finally ( and sorry for the amount of questions!) the annual glare profile is climate based. So if I go to dgp file and say that for a specific time the DGP is say 20% and I want to generate an image for this specific time I have to make use of the custom sky. What values do I have to enter for direct and diffuse horizontal irradiances?

Kind Regards,

Kostas

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Hi Kostas,

Now about the point in time glare image ( I am making use of the Gund_111 and I generate the interior view) something is going wrong. Please have a look in the image provided.

What do you find wrong with the image? Is it because the view is so far away from the window? It can be difficult to get the proper view for glare calculations because the default lens length in Rhino is 50, which makes it seem like you're looking through a telescope, but a glare calculation generates a fisheye image from the camera location. It helps to set the Rhino lens length to something lower like 10 or 15 when setting up a glare calculation.

Finally ( and sorry for the amount of questions!) the annual glare profile is climate based. So if I go to dgp file and say that for a specific time the DGP is say 20% and I want to generate an image for this specific time I have to make use of the custom sky. What values do I have to enter for direct and diffuse horizontal irradiances?

You have come upon one of the things that is not super-nice about the DIVA inputs (to be corrected), which is that the DIVA weather files use direct normal and diffuse horizontal irradiance while the DIVA Perez sky input takes direct horizontal and diffuse horizontal irradiance. Basically you can find the direct normal and diffuse horizontal irradiance from the .wea climate file (c:\DIVA\WeatherData\USA_MA_Boston-Logan.Intl.wea for example) that is used in the annual DGP calculation. Knowing the position of the sun, you could translate to direct horizontal with a geometric correction. For a sunny timestep with a large DGP value, it is probably OK to use the CIE Clear Sky with Sun sky distribution.

Best,

Alstan

Hi Alstan,

What do you find wrong with the image? Is it because the view is so far away from the window?It helps to set the Rhino lens length to something lower like 10 or 15 when setting up a glare calculation.

Yes I followed your advice and the image looks much better.

Basically you can find the direct normal and diffuse horizontal irradiance from the .wea climate file (c:\DIVA\WeatherData\USA_MA_Boston-Logan.Intl.wea for example) that is used in the annual DGP calculation. Knowing the position of the sun, you could translate to direct horizontal with a geometric correction

Thanks for the clarification. Now about the geometric correction you mean just to multiply the normal irradiance by sina where a is the altitude of the sun.

Kind Regards,

Kostas

Thanks for the clarification. Now about the geometric correction you mean just to multiply the normal irradiance by sina where a is the altitude of the sun.

Hi Kostas,

Basically yes, but it should be a function of the azimuth as well. As I mentioned before the next version of DIVA should use more intelligent inputs.

Best,

Alstan

Hi

I've a different problem, when my geometry gets more complex the glare study returns with full imperceptible glare results.

I've attached my simulation results for those with less geometry and the more geometry that doesn't work.

I've also tried pre-meshing the geometry before running the simulation.

Do let me know how I can fix this.

Attachments:

Hi Aloysius,

Its difficult to tell anything from your results images. One thing that often happens is that it can be difficult to locate the viewpoint in the Rhino file for simulations. I recommend to render a quick fisheye view in each file. See the below screencapture.

If the views in both files look similar, could you post the two Rhino files in question?  If they do not look similar, decreasing the lens length of your Rhino view helps to get a more realistic idea of the Rhino camera location.

Best,

Alstan

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