Ladybug Tools / Spider RAD Viewer - Release 7.3 / 2018-10-06 / Polygons with many vertices: now OK

Today together with @TheoA and @mostapha , I am very pleased to reveal another brother of Aragog Spider viewer – RAD viewer - new brother of Ladybug Tools – Spider. As always, it is free and open source, 3D and viewable in your browser. Finally your .RAD file can viewed on any device. This script was first shown by Mostapha at The 17th International Radiance Workshop 2018


Spider RAD Viewer

Read Me

  • Select, open, view and manipulate Radiance RAD Files

  • Open file or files via

    • Operating system dialog box - single or multiple files
    • URL - remote or local - supplied by a location.hash update - single files only for now
  • Select files from lists of links to available online sample RAD files

  • Display RAD files in interactive 3D with rotate, zoom and pan

  • View RAD file data

    • Native text format
    • Translated to JSON
  • Basic look-up table supplies a basic polygon colour palette if no material specified

  • Handles openings in surfaces moderately well

  • Update scene settings: rotation, wireframe mode, edges visibility, surfaces opacity

  • Written in plan-vanilla JavaScript

    • Single dependency: Three.js
    • No need for a server: run locally or offline

Read Me: Spider RAD Viewer Cookbook

More scripts are available in the Cookbook


Sweet work @TheoA, @MichalDengusiak and @mostapha! I already used the gbxml viewer a ton, can’t wait to try this out as well.

As always, excellent work and can’t thank you enough for it! I was so tired of viewing the RAD files in ecotect (the HB RadViewers were always too slow for large models due to grasshopper limitations)

@mostapha Shouldn’t this be shared to the Radiance discourse as well?


For sure it should be.

I am posting as we speak … :slight_smile:

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The Ladybug Tools /Spider RAD viewer is now up to R5.

Here is the link to whatever is the latest/current release:

This release includes the pop-info for each surface in the main script.

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thanks @TheoA
All links updated

HI @TheoA, @MichalDengusiak,

Are some limitation in the file size , number of polygons, etc… ?
I tried to view 8MB rad file and my browser gave it up.

Peter Z


Are some limitation in the file size , number of polygons, etc… ?

Good question. I don’t know yet. Here is a screen capture of file with over 17 MB of data:

The frame rate is down to around 5 frames per second, but the pop-up response is near instantaneous

The file was loaded on a Laptop with a core i7, 16 GB RAM and an Nvidia GPU. The thing is that it took two or three minutes to load.

I have loaded a file that is over 25 MB on the same machine, but I has ti be very patient.

But your question raises a lot of issues. There are many things we can do about large files:

  • Display data progressively while loading - so you know that file is actually loading
  • Better reporting if there is an issue
  • Adding web works to add more CPUs to the loading process
  • Merge individual surfaces into larger meshes to compact the data

This script is only a few weeks old and there a bunch more things that can be done to make it better.

So please do ask questions, And if you can share files even better. The more files that get tested the better the script will become.



Image of Manhattan created on a Chromebook ( with older version of viewer )

And here is the 500 KB whale on a phone

that´s cool,
when I used firefox it crashed, but with chrome it worked out after 1-2 minutes, but it was really really slow.
But as I understand it should always come down to the specs of the computer, (GPU or CPU ?) and not to browser difference

@PeterZatko please share your file so we can test on different browsers and check settings

Hi @MichalDengusiak.
see in PM


Thank you for sharing ( privately ) the file in question. It is precisely the type of file I was looking for: many triangles and a reasonable number of materials.

I should now be able to assemble the triangles into groups of meshes. This will enable the merging of vertices and more.

Fingers crossed we get a small faster model. I will try to build some of this into the next release of the Viewer. Again, thanks for sharing.


Hi @TheoA,

thank you to doing it.
I´m quite sure everyone who works in our field has tons of such models, and until now, the good old ECOTECT was the only program able to visualize it, but just in wireframe, so I hope you will succeed.
Fingers crossed, and if you have any question let me know.

Peter Z


Please have a look at:

This is the first pass at an experimental script designed to open large files.

It opens a 72 MB file in four seconds or so, but still has issues:

  • Only a singe color is displayed for all surfaces
  • Some quadrilaterals are not triangulated properly

In this version you can load multiple files one at a time using the file dialog box. I’m not sure if this is a bug or a feature. Click the script title to reload a fresh page.

The files used to generate this screen amount to just under a hundred MD. Frame rate is about 60 fps on my machine.

Fingers crossed: colors in next release

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@TheoA, oh yeah,

Loads in like 0.0001 millisecond, and frame rate stay high, in other words, .works as a charm. The colours or some info at hover over would be appreciated

thank you for the superb work Theo !!!

Peter Z

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Spider Rad Viewer Triangles Only R6.1

Beginning to get some color along with the speed.

There are still many issues with triangles appearing and disappearing incorrectly. Only polygons with three or four vertices are drawn. No Spheres, cylinders and no 10 vertex surfaces with ‘openings’.

Also if the details of a material are not specified then a random color will be displayed. This happens in the private file you sent me for example.


You will note that your Warwick file displays very quickly in the RAD Viewer - quicker than the gbX/ml Viewer. It should, however, be possible to bring similar speeds yo the Viewer in future releases.

BTW, feature requests are good and bug are not needed. As you will see there are many issues - but in fixing them I may also be able to add any tricks you might crave.

Hi @TheoA, would it be possible to show the camera position and view direction somewhere on the screen? This would be useful as it would allow the use of those values to create renderings for point-in-time and annual simulations. The full list of view parameters that can be specified within radiance can be found here: (all the ones that begin with -v , for example -vp view point and -vd view direction are the ones that I am asking about).

Radiance allows a lot of flexibility in how the final renderings can be generated, however, one needs to be sure that the view settings have been set correctly before proceeding with the actual task of raytracing (which can take a few minutes to a few days). Right now one has to start a 3D software like Rhino, Sketchup etc to get the view info. Objview, the native Radiance viewer requires some getting used to and is controlled through command line options only.


(PS: If you think this is something that can be done and need more detailed explanations, please feel free to ask)

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