Shadows not correct in Renders

[Anonymous]

hi everyone,

sorry inadvance if this is somewhere else on the forum, so far I haven't found anything and I can't figure it out. I'm still learning Archicad, but I'm having problems with my renders.

I put in a sun object to get a nicer shadowing effect on a set of stairs that are outside.
When I change the time of day it shows it correctly changing in the perspective window, but when I render it always comes out the same way, with the shadows still stuck on a midday sun rather than sunset/evening that I'm aiming for.

Other than adding in a sun object, the only thing I've changed from the default is unticking the sun box in the settings and selecting lamp rather than off/hard in shadows (was following this http://www.graphisoft.com/ftp/techsupport/documentation/developer_docs/BasicLibraryDoc/11/LightWorks...)

Please help!

[David Maudlin]

Eva:

The Sun Object was useful for earlier ArchiCAD versions (your link is for AC 11 documentation), but I would recommend just using the built-in Sun (PhotoRender Settings > LightWorks Environment > Sun > Realistic Sun (and check the Sun option under LightWorks Effects > Light Sources). The Realistic Sun has settings for soft shadows, start with the default values. This will tie the sun's position to Perspective Settings or Camera Settings (if you are using Cameras). It will also be part of a saved View. It is possible with the Sun Object that the sun's position is not tied to the Perspective Settings, or you need to Rebuild the 3D Window to get the correct sun position.

Looking at the Help files, there is no change between version 12 and 17 for Lightworks, so I think these were not updated when the Realistic Sun was added. Dwight Atkinson has a very useful book on LightWorks, you can also search this forum for his posts.

You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.

David

[Anonymous]

Thanks David,
I didn't realise that was for AC11, I've done exactly what you said and it's working!
Could you just tell me how I can adjust the soft shadow settings with the Realistic Sun? All I can see is Shadows, Number of Samples and Diversion Angle?

Thanks

[David Maudlin]

Eva:

The Diversion Angle will control the softness: higher values give blurrier shadows, lower values sharper ones. The Number of Samples controls the resolution: higher values have higher resolution but take more rendering time. You can set up a very simple scene (one wall on one slab) to test various values to find the result you want while minimizing rendering time. There are similar values in the Sun Object.

Thanks for updating your signature.

David