Exterior lightworks render help

[Anonymous]

Whats the best settings for the sun & sky objects for an external render in lightwork? I have spent hours trying to find the a good setting but i am having problems.

[Anonymous]

Hi Johnson,

You have asked quite a vague question, which is probably why you haven't had much response!

What are you looking to achieve with the render? Give us an idea of the 'feel' you are looking for.

It would be useful to post a preview of the render as you have it at the moment, then we can maybe suggest better ways to light it.

[Anonymous]

Sorry, my comment was quite general. I ve attached an image of the render I m working on, as you can see under the canopy its really dark.

I have turned off the archicad sun, and I am using the sun object which is set at 75%, I have the Sky object on, and another sun object acting as the under sun.

I did try to put a general light under the canopy but it then made it all look to bright.

I Really, interested in what sun object settings ect other people use and how they position them. I have got the '' Lightworks in ArchiCAD'' book by Dwight, and have read some of it. But the section about external renders is quite sort.

Any comments or help would be really appreciated.

Cheers

John

[Anonymous]

Render attached

[Anonymous]

Johnson wrote:
Sorry, my comment was quite general. I ve attached an image of the render I m working on, as you can see under the canopy its really dark.

I have turned off the archicad sun, and I am using the sun object which is set at 75%, I have the Sky object on, and another sun object acting as the under sun.

I did try to put a general light under the canopy but it then made it all look to bright.

I Really, interested in what sun object settings ect other people use and how they position them. I have got the '' Lightworks in ArchiCAD'' book by Dwight, and have read some of it. But the section about external renders is quite sort.

Any comments or help would be really appreciated.

Cheers

John

Dwight covers this or search for "undersun" here.
http://archicad-talk.graphisoft.com/viewtopic.php?p=134473&highlight=undersun#134473

Dave

[Anonymous]

Looks pretty good so far!

Firstly I'd recommend using the built-in sun instead of the Sun-object for the main lighting task. I'd try setting it quite brightly to start with at 150% and then back it off if it is too much when combined with the sky. Set it to 'Realistic Sun' with Shadows, Number of samples 100, and a Diversion angle of 0.50. This will give you nice crisp shadows.

Make sure camera and ambient are turned off for the moment.

Try setting a Sky-object to 'Realistic Method' with the number of samples at around 300. This will slow the rendering down a fair bit, but it gives a better 3d feeling. You can reduce the no. of samples to preview the render; it will just look more grainy. Have this set to mid power to start with (40-50%)

Most importantly, make sure you use a very-slightly-yellow colour for the sun and a very-slightly-blue for the sky.

Don't forget to set the location and north point correctly in the main sun settings if you need it accurately lit. The built-in sun and ambient takes their colour from this dialog box also.

The undersun should be set fairly low powered and it colour should probably be a light blue also.

If the render is still too dark try enabling the built-in ambient light to boost general light levels.

Set the Anti-aliasing to one notch below best for previewing the image. It will use all the cores in the machine to render. 'Best' only uses one core, but looks better.

[Anonymous]

Will give that ago over the weekend, also thank you for your help Peter.

Cheers

John

[Dwight]

Sorry to be so long in responding since still suffering with serious illness.
But when a fellow's book is observed to be inadequate, it begs a response.

As far as the illustration in question - this seems much more a display gamma issue than a lighting issue. I pulled the levels on this image in Photoshop and fixed it.

Sometimes users cope with glare on highly reflective materials - like metals - by reducing light power - the 75% decision.

It is usually the material that needs roughness added or specular reflection reduced.....

Note that since my book was initially issued for Archicad 9, two supplements outlining sun changes were made - where internal sun supplants the Sun Object as a primary light source. Registered book owners received notice of these updates and one update was posted on this forum for all to use.

Furthermore, since the poster suggests a weakness in my book regarding exterior views, I direct him to page 27 [and the supplement] where a typical exterior rendering is developed step-by-step, page 150 where an aerial view of a project is lit and inserted into a context image, page 160 where a city block of flats was lit and illustrated in several methods and page 178 where an entire commercial project is lit and inserted into a context with expert materials matching a photograph.

[Anonymous]

Peter wrote:
Looks pretty good so far!

Firstly I'd recommend using the built-in sun instead of the Sun-object for the main lighting task. I'd try setting it quite brightly to start with at 150% and then back it off if it is too much when combined with the sky. Set it to 'Realistic Sun' with Shadows, Number of samples 100, and a Diversion angle of 0.50. This will give you nice crisp shadows.

Make sure camera and ambient are turned off for the moment.

Try setting a Sky-object to 'Realistic Method' with the number of samples at around 300. This will slow the rendering down a fair bit, but it gives a better 3d feeling. You can reduce the no. of samples to preview the render; it will just look more grainy. Have this set to mid power to start with (40-50%)

Most importantly, make sure you use a very-slightly-yellow colour for the sun and a very-slightly-blue for the sky.

Don't forget to set the location and north point correctly in the main sun settings if you need it accurately lit. The built-in sun and ambient takes their colour from this dialog box also.

The undersun should be set fairly low powered and it colour should probably be a light blue also.

If the render is still too dark try enabling the built-in ambient light to boost general light levels.

Set the Anti-aliasing to one notch below best for previewing the image. It will use all the cores in the machine to render. 'Best' only uses one core, but looks better.

This is one of the most helpful posts I've seen on this subject. I have a question to add. Should the "get model data during rendering" checkbox be checked?

[Anonymous]

Don't take my recommendations as gospel; they are just the default settings that I use which I know will give a decently lit render. I would always adjust these settings and add fill lights to suit the context.

Whatever John decides to do, I would at least sharpen up the shadows by reducing the diversion angle of the sun.

Wrathchild wrote:
Should the "get model data during rendering" checkbox be checked?

To quote the Help file -

Get model data during rendering process: Check this box to allow two processes to proceed simultaneously when you execute a PhotoRendering: ArchiCAD will analyze model data at the same time that it generates rendering effects for the model. As a result, the rendered model might take longer to appear in full on screen, but the process will require less memory.

I've no idea if it makes any difference, I've never tested it!