Sun Panel Stuck

Yesterday I was using the sun panel to see what the shadows would look like at different times of day. After a while the setting just “stuck” and no matter what I seemed to do to the sun panel controls, the shadows would not move. Early it was working fine. Does anyone have any ideas about what I’m doing wrong? I shut down the program and reopened the file in the 32 bit version and it went back to working. Any help is greatly appreciated

I haven’t heard of this issue before so I’m wondering if the settings changed in the Sun panel. Please post a screenshot of the Sun panel if something doesn’t seem like it’s working right. My hunch is that maybe you were using manual control but then it got turned off. Also, you mention using the 32 bit version when opening the file again but was this the same version you were using when it stopped working?

I did try the manual setting at some point but that has since been toggled on and off several times to try to get the shadows to budge. It was the same version. I recently installed both the 32 bit version and the 64 bit version to my desktop here at work. I did discover that I had left my home version of Rhino on while I was at work yesterday. Could there have been some licensing issue associated with this breakdown?

I don’t think that would be involved with this no.

If there is a reproducible set of steps to see the Sun shadows stop working please let me know. If it also only seems to happen with a certain file, it would be great to get that sent in to or uploaded to Rhino - Upload to Support

Another guess would be to check Options>View>OpenGL You might need to update your driver or the GPU may be stretched to it’s limit given the size of the scene.

Hi Michael,

Just to be sure, in order do to adjustments on the sliders, the option manual control needs to be checked:


Here’s the OpenGL info…I’ll send you the file as well. It will probably
be coming from another email address (

Thanks for all the help.


Take a look over this page on Quadro settings…

You might want to try using an older driver as a test.

Quick fix to try:

I would delete the sun, just in case it has been corrupted. Place a new one and see if the settings work better. There’s not that many settings that will need to be re-entered.

This happens with other V-Ray features from time to time, so after a few minutes of tweaking and swearing, I like to see if a “punt” works better. Usually, I save a lot of time and move on.

Hi Dave-

Thanks for this. Very helpful. Would you mind telling this noob how to
display light objects so I can delete them or change their intensity?



Lights should be visible, unless they are hidden or on a layer this is turned off. If you can’t see them, then zoom WAY OUT (or do a Zoom All) They can sometimes be hiding up high or off to the side.

There’s a lot more to Architectural Lighting, so check out my lynda course. You can preview 10% for free and here’s a 10-day free trial if you want to see the whole thing.

I’ve tried showing everything and zoom extents. No luck. Is there maybe a
preference someplace that either displays lights or doesn’t? Is it because
I created the lights in the sunpanel? Thanks for your help Dave.

Can you provide some screenshots of what you see in the Sun panel? You can load a Rhino Sun into the Sun panel but not regular light types like Spot or Rectangular for instance. Also, are you using a specific rendering plugin? A few screenshots of what you see should help in helping. This may not be related to the original post too so feel free to Reply as a linked topic.

Hope this helps.

Here is one with the lighting window open.

Thanks, I understand the confusion now. The Sun and Skylight are not regular lights that you can select and delete. You can disable them and adjust intensity in the case of the Skylight or position in the sky for the Sun. If you’d like a light source that is like the sun but can be selected directly, use a directional light which you can create from the Render toolbar tab.

Does that help?

Sorry for my added confusion. I had assumed you were using V-Ray, where all lights AND the sun show up as handy icons for easy editing. See attached example.

Just so I understand, are you saying that if I use the sun panel, I can’t adjust the intensity of it? Sounds like maybe this sun panel is meant mostly for analysis of shadows and shouldn’t be mixed with more “artistic” endeavors. I just have a client commenting on how the model looks like “Hiroshima” because the sun is creating such high contrast.

The suns position in the sky can be adjusted which controls the color and intensity of it. If you have the skylight on as well and are using an HDRI in an environment or a white color for that matter, that may also be creating the extreme contrast. Material properties are also a factor of course as white reflective surfaces will look different than matte gray ones in the same lighting.