-- Shadow Mystery --



Why does the shadow in this picture give me a stripe. It seems like the shadow of the rake or fascia board, but not the roof plane, itself. As you see from screen save, I checked the cast shadows and receive shadows box. You might not be able to tell from screen save, but the roof plane is highlighted to load entity info.

Always appreciative



If you can upload or link the model, people here can help better.

As a wild guess, have you turned on cast shadows for the underside of the roof? The shadows from the top side will cast onto the inner face of the bottom side and not be visible!


Is any of the roof in groups/components? It is possible to have a face that is set to cast shadows, but if the container is not, then no shadows will appear…


I checked the underside soffit-porch ceiling plane. It also had cast-receive shadow boxes checked. I have imported a bunch of furniture from 3d warehouse and pictures for background. I think the size prevents me from uploading file. What is the limit for uploading. I have run into this before.

Thanks Eli


If you exceed the upload size limit, you have to either prune down the model to fit or put it on a file sharing site and post the link here. BTW there was recently a glitch that was rejecting uploads, claiming they exceeded a (non-existent) 5kb limit. That should now be fixed, but the limit is still 3MB.


Upload it to the 3D Warehouse and paste the link here.


to me, it looks like the underside and the topside of the roof is somehow set to not cast shadows, and the side of the roof it set to cast shadow.

Although I think you have already confirmed that it is not.


I think you’ll find there are more problems than that, notice the posts holding up the porch roof don’t throw shadows either. And are bright at the top and dark at the bottom.


That is true, but perhaps the columns are also checked off to not cast shadow.
The side of the roof seems to be casting shadow onto the column as well.

The bright and dark of the column feels that it is result of smoothed edge that the model seems to have throughout. (turned off/all smoothed edges do not help for us to observe either)

I guess wait and see if OP can upload at least the partial of the model.


I’m going with a problem in the layers caused by importing. Note the entity info showing “Face” not on layer0.


oh, just noticed that. that well can be.


This is my attempt to draw what you draw the same image. I made a 2d square, rotated it, and made a horizontal square, stretched into a box, then deleted the surfaces but not the line. You see the cast shadow is specified. And it does. However, it does it also when not those boxes are not specified. Therefore, I am not able to recreate what you show.


This model originated in datacad and imported into sketchup. All entities were grouped and on their original layers. However the roof was not grouped. I must have drawn it in Sketchup. I moved the plane highlighted back to Layer 0.

The columns were part of original import. It is grouped. The shadow boxes are specified.

Where is the smoothed edge command?

Thanks guys.


I’m not sure what to say really. Without the model (easily uploaded to the warehouse) it’s impossible to diagnose your problem.
As i mentioned above i believe it is due to importing layer errors from the other program. It affected your last model and until you address that i think you will continue to have problems.


I have uploaded the model as the screen save shows. However, I do not see the url. Doing a search in 3d warehouse, it now shows up, using the name, Shadow Mystery

Thanks for your help.



I can’t find it in the 3DW. Did you make it publicly visible?


The roof looks like it is a single skin face, and it appears to be using an image as its texture.
I suspect that the material’s opacity is <=70% ?
So it’s like a sheet of glass, and therefore it doesn’t cast a shadow.
Edit the Material and see what its settings are…


Is the model very (more than about a mile) far from the model origin point, or does it include objects that are situated far?
To me some things in your screenshot (and that you cannot reproduce the issue in a new clean file) point to OpenGL issues caused by large model extents. Or are you using some rendering plugin that affects the real time display?



I have gone back and edited back to public. Will I be able to remove when I am done.

I have been working with the model, adding geometry in the planes in question. The shadows have returned. Perhaps I should redraw the roof and columns.

I am working with a copy. It was located 1000’ from red line axis. I moved it to check if that made a difference.



You’ve been showing us a pretty limited snippet of your model! Lots there to investigate as to the source of your problem!