Is it possible to get LBT 1.2.0 working with Accelerad?

After changing my workflow from legacy component to the new LBT1.2.0, I notice the Accelerad is incompatible, the error message:

  1. Solution exception:The installed Radiance is not from 2020/9/3 or later.
    Download and install the version of Radiance listed in the Ladybug Tools compatibility matrix
    1.4 Compatibility Matrix · ladybug-tools/lbt-grasshopper Wiki · GitHub

    The Accelerad greatly speeds up Radiance calculations for large buildings through GPU, but it’s a long time since the last update. Is there some way to get it working?

Hi @miraclema, there is no incompatibility between LBT 1.2.0 and Accelerad. How did you install Accelerad on your machine? The component is trying to ensure you are using the correct version of Radiance but it might be getting it wrong by checking the release date for accelerad instead of radiance itself.

cc: @chris

I recommend using the “HB Check Versions” component to check see what Ladybug Tools thinks your installed version of Radiance is. Like you see here on the lbt-grasshopper wiki:

I think what’s going on here is that @miraclema has replaced Radiance’s rtrace command with the one that comes with Accelerad and since we use rtrace -version we get the version for Accelerad distribution instead of Radiance itself.

@MingboPeng, is there a better way to get the version of Radiance that is installed? We need one of the commands that are not overwritten during the Accelerad installation:

Even i have the same problem.

Accelerad overrides the version from Radiance. I think the best way to fix this is @Nathaniel updates Accelerad with the new Radiance and append his Accelerad version next to original Radiance version instead of overriding it.

You can search the Accelerad version string for the Radiance version. However, there is no guarantee that Accelerad versions correspond with “official” Radiance releases.

You can also use mkpmap -version, as this is not overridden by Accelerad.


Brilliant! This will be a quick and easy fix.

Thanks for the tip, @Nathaniel .

I just merged a PR that will change our Honeybee Radiance version check to use mkpmap instead of rtrace, which should prevent this situation:

Also, for anyone needing a workaround who doesn’t want to upgrade to the LBT development version right now, you can always bypass the Radiance version in Ladybug Tools by removing the radiance_check=True inside the recipe component like you see here:

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Thank you Chris for this fix. But when I tested by updating to 1.2.2, it still tells me “The installed Radiance is not from 2020/9/3 or later.” And after I removing “radiance_check=True”, it can’t calculate. I record the screen below:

The Chinese words means: “This file is being used by another program and cannot be accessed by the process”. Even I use the administrator mode it remains the same.

Below are the last lines:

Hi @Teja5zz , can you test the new version? I want to know whether there is something with my system.

After removing the radiance_check condition ,it is working. Thanks for the update @chris

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4 posts were split to a new topic: What folders are acceptable for Radiance simulation?

is there a guide somewhere on getting the current release setup with accelerad?
… not something I’ve any real familiarity with in terms of srcn :sweat_smile:

Hi @TrevorFedyna,

The “Use Accelerad in your workflow” should work. Use HB Config to find the Radiance folder (probably C:\Program Files\ladybug_tools\radiance) that LBT is using - replace the files in that folder.



This looks to be just what I was looking for thank you!

Hi chaps,
I have followed the steps indicated in Accelerad Documentation and managed to get Accelerad to work with LBT 1.5.

WHile performing very well on two example files packed with the LBT 1.5 installation archive (for daylight factor and annual daylight), I did run a simulation for about 70-75 rooms, and approx 14000 sensor points and this seems to always leed to a crash. Is this something you can help with?


Immagine 2022-11-30 231416

Hey @andrea.botti ,

This sounds like a limit that is internal to Accelerad or your graphics card and @Nathaniel is probably the best to answer. If he doesn’t see it here on the forum after a while, you can probably ask it on either the Radiance forum or the Accelerad Github. Searching both of those places is also a good idea.

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Hi @andrea.botti,

The error message in your screenshot appears to come from the OpenGL driver. Accelerad does not use OpenGL. In general, if Accelerad experiences an error coming from its own kernel, that error will be reported through the standard error stream from Accelerad, not through a dialog box.

My best guess is that there is some conflict between the OptiX kernel used by Accelerad and the OpenGL kernel used by some other program. Possibly, this is the result of TDR, but it’s hard to tell. It could also be a bug in one of the drivers, which might be solved by updating your graphics drivers (or rolling back if you are using the latest).

If these solutions don’t work, then we’ll need to look at the command line output messages to see what errors Accelerad is reporting, possibly with the -gv verbose output option. We’ll also need to look at what hardware and driver versions you are using. You can post this on the Radiance forum.