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Renderworks : cyclorama light not shown

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Hello everyone,


I have a rendering problem with Renderworks.


I created a cyclorama with the Soft Goods tool and created a special texture for it, to allow it to be lit from the back.

The texture settings are :

  • Color : White 100%
  • Reflectivity : None
  • Transparency : Plain 99%
  • Bump : None
  • Cast and receive shadows
  • Override Indirect Lighting, Emit Light and Receive Light checked.


With these settings it works well with OpenGL, but with all the RenderWorks (I tried Fast, Final and Custom with different settings) modes the scrim is just black.

And I can't only use OpenGL as I want to use more than 8 lighting instruments in my renderings.


Anyone ?

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The key to it is the reflectivity shader. This should be set to Backlight. You may also want to add an additional surface that contains a see-through glow shader.  Light dissipates across a scrim and this is a good way to show it. 

I've included a file with an example. Scrim.vwx


If you want to just show a smoothly lit cyc, then a good and quick way would be to just have a glow shader applied to a Nurbs surface.


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Thank you for the quick reply !


So, I tried with your file (by copy-pasting the group and exporting the texture) and… it's even stranger. It work well in your file, however in mine in OpenGL it's just black and in Renderworks it' gray.

If I set the intensity of the texture to 90%, I have something in OpenGL, but still nothing in Renderworks.

I attach two screenshots to show you how it renders.


Maybe there is a problem with the lighting instruments… ?


Your second solution isn't suitable for me as I want to use the lights behind the cyc.


OpenGL (Opacity 90%).png

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I don't really understand what your two images are. Can you describe each one for me and what you are doing?

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Oh sorry, I forgot to name them.

The first one (gray) is a Renderworks rendering with the group and texture of your file applied in my file.

The second one is an OpenGL rendering of the same thing but with the intensity of the texture set to 90% (if I keep the intensity to 10% like in your file, then in OpenGL it's black). It's the only case where there is something approaching my needs (where I see the light through the cyc in fact). But in Renderworks the cyc is white in this case.

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Are you absolutely certain you are using the texture I sent over on your cyc surface?


Colour: Off white

Reflectivity - Backlight:


Transparency - Plain:



Works fine here. I've added a lighting device instead of using a standard light object.


Open GL:5a8997d91f8ef_ScreenShot2018-02-18at15_11_50.thumb.png.fa6c96004d24f1ba7e669b931bd4472c.png


Fast Renderworks:5a8997f65c050_ScreenShot2018-02-18at15_12_05.thumb.png.77704a9a2265ddf0258591a7f948af9d.png


Also check your lighting options:




If you still have problems then PM your file and I can troubleshoot it for you.....


BTW, if you have your transparency set to none, and backlight on Open GL won't understand that whereas Renderworks will. Basically, not as much as one would like is enabled on OpenGL in Vectorworks.




Edited by markdd

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Ok, so I worked a little bit more in my own file with the elements you sent me. Apparently it's the lighting instrument (ADB ACP1000) which has a problem, because with another one (tested with an ADB F101) it works well (like on your screenshot).

The odd thing is that in OpenGL the light is shown, but not in Renderworks.

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Yes. The ADB fixtures don’t have a lens texture attached (or it’s incorrect) which is a fault with the Vectorworks symbols. You’ll need to edit the symbols then.......

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