topic Re: LightWorks Sun in Visualization

LightWorks Sun

Dwight — Thu, 11 May 2023 12:11:07 GMT

Has anyone managed to make a soft shadowed LightWorks sun uising the native sun rather than the SunObject?

If so, can you post the extreme comparison?

Lets just confirm that all of those sliders aren't actually connected to anything.

Re: LightWorks Sun

Ben Odonnell — Wed, 02 Feb 2005 10:34:03 GMT

Dwight,
Have tried it many a time but to no avail. It seems that if you want soft shadows you need to use the Lightworks sun object.

Cheers.
Ben

Re: LightWorks Sun

Karl Ottenstein — Mon, 07 Feb 2005 23:14:31 GMT

Ben wrote:
Have tried it many a time but to no avail. It seems that if you want soft shadows you need to use the Lightworks sun object.

Same experience.

Karl

Re: LightWorks Sun

Dwight — Mon, 07 Feb 2005 23:34:17 GMT

Okay.
Graphisoft says the effect is subtle.
Too subtle for me.
Just to confirm, since playing with light, is an exercise in my… book…

Left is hard sun 500% strength no ambient.
Right is sun as soft as it can be made, 500% strength no ambient.

Can anybody see a difference?

Re: LightWorks Sun

fuzzytnth3 — Tue, 08 Feb 2005 01:13:12 GMT

If you overlay the two renderings in Photoshop by copying and pasting onto a new layer. Then use the Invert command in the Adjustment menu and finally change the top layer mode to Multiply then what is left is the difference between the two images.

As Graphisoft say it's a very slight difference

Re: LightWorks Sun

fuzzytnth3 — Tue, 08 Feb 2005 01:18:30 GMT

Another way to look at the same image is to set the Layer mode to Difference

Re: LightWorks Sun

Dwight — Tue, 08 Feb 2005 01:35:05 GMT

????
what can this tell us about soft shadows?

Re: LightWorks Sun

Ben Odonnell — Tue, 08 Feb 2005 07:28:36 GMT

Dwight wrote:

Can anybody see a difference?

No.
Ok one can play with the images in Photoshop to see the very subtle differences, but to the naked eye you can't see any difference.

Cheers.
Ben

Re: LightWorks Sun

Anonymous — Tue, 08 Feb 2005 07:41:52 GMT

Hi
Wherewith longer research lightworks all the more be convinced do you Graphisoft hasn't everything aplikovano proper.
Effect Foglight I am experimented 4 o'clock than I am it opening nevertheless me no-goes item LWA_LIpoint_intensityunits
Sun that'll similar.

Re: LightWorks Sun

fuzzytnth3 — Tue, 08 Feb 2005 09:46:21 GMT

Dwight wrote:
????
what can this tell us about soft shadows?

What I think it shows is that the difference between the two images isn't in the shadows but elsewhere in the image.

If there was absolutely no difference between the two images you would see just a black image when overlaid as I have done. As it is you are seeing some parts of the image and therefore Graphisoft are correct there is a difference albeit not in the shadows and it's blooming hard to spot

Re: LightWorks Sun

Anonymous — Wed, 09 Feb 2005 07:44:35 GMT

manual lightworks :

[ "shadow type"]
This argument is used to specify whether hard-edged shadows (produced by ray casting) or soft-edged shadows (produced by shadow mapping) are created. The default value of this parameter is LI_SHADOW_TYPE_SOFT; whenever this is so, shadows maps have to be explicitly pre-calculated by the application, prior to rendering, by calling LiLightCreateShadow.

Note that when multiple light samples are evaluated, as is often the case with the area light source shader, so-called "hard-edged" shadows will not always result -- the term is derived from the appearance of ray-cast shadows when a single sample is being evaluated. Four samples will lead to 4 levels of grey in the shadow penumbra and forty samples will lead to 40 levels of grey -- neither case will appear "hard-edged".

Re: LightWorks Sun

Dwight — Wed, 09 Feb 2005 14:53:03 GMT

In the case of my examples, using the lightworks sun [not the lightworks sun object: a lamp] it was not possible using the provided controls to achieve a soft shadow.

Does your message mean that you think this feature can make a soft shadow? Or that it should, but doesn't?

If you think, regardless of any real experience we are having, that the built-in sun can make a soft shadow, could you please list the setting to do so?

Making reference to programming terms is not helping users who must rely on the interface controls.

Re: LightWorks Sun

Anonymous — Thu, 10 Feb 2005 07:37:58 GMT

Now I think do you sun cannot do soft shadow
Parameter soft and hard have influence on overlapping shadow.(addition)
When I'll have free time
I yet I will do experiment with lamps in GDL type SUN thereby go round interface render for setting Sun.

Light Shader - LWA_LIsun - Sun
LWA_LIsun_altitude Altitude FLOAT
LWA_LIsun_azimuth Azimuth FLOAT
LWA_LIsun_north North VECTOR
LWA_LIsun_up Up VECTOR
LWA_LIsun_intensity Intensity FLOAT
LWA_LIsun_color Colour COLOUR
LWA_LIsun_colortemp Colour Temperature FLOAT
LWA_LIsun_mode Mode BITFIELD LWA_sunautomode default: 0
LWA_LIsun_latitude Latitude FLOAT
LWA_LIsun_longitude Longitude FLOAT
LWA_LIsun_time Time POINTER
LWA_LIsun_skytype Sky Type POINTER
LWA_LIsun_shadows Shadows BOOLEAN
LWA_LIsun_shadowtype Shadow Type ENUM LWA_shadowtype default: LWA_soft
LWA_LIsun_shadowtrans Shadow Transparency BITFIELD LWA_shadowtrans default: 8
LWA_LIsun_shadowacceler Shadow Acceleration BITFIELD LWA_shadowacceler default: 0
LWA_LIsun_shadowresol Shadow Resolution INTEGER
LWA_LIsun_shadowquality Shadow Quality INTEGER
LWA_LIsun_shadowsoftness Shadow Softness FLOAT
LWA_LIsun_intensityunits Intensity Units ENUM LWA_intensityunits default: LWA_empirical
LWA_LIsun_scattering Scattering BOOLEAN
LWA_LIsun_shadowtolerance Shadow Tolerance FLOAT

Re: LightWorks Sun

Dwight — Thu, 10 Feb 2005 14:16:53 GMT

i've moved past that, now. It is just that when writing a book, you look like a boob if you make a mistake like saying that a tool that appears to make soft shadows and actually doesn't, does.

I have quite clearly resolved softness using the sunobject and skyobject - fairly nice tools.

BTW: still looking for LightWorks renderings for the book. Had very few takers so far.
Free book if selected.

Re: LightWorks Sun

Anonymous — Fri, 11 Feb 2005 10:00:35 GMT

Sory
Perhaps because of my English you are it misapprehend .
I not to speak about object lamp sun .The be inside written by the help of lamps "LWA_LIdistant"
A soft shadow smoothing-out by the help of more lamps.
From you would of such response at of your knowledge did not expect (

Re: LightWorks Sun

Anonymous — Mon, 04 Apr 2005 01:36:00 GMT

I have a further query - how have users found the sun and sky objects re. updating to match the sun in predefined view settings? (when auto checkbox selected)?

Graphisoft have given an 'improved' tool in ArchiCAD9 for better rendering. "We" are all pleased as we can now integrate rendering into the workflow, and not have to write intermediate files, change apps and render etc...in theory anyhow.

In practise I have the following "bugbears" -

The interface to apply/change/tweak materials is very clunky when one tries to "do it all in ArchiCAD". I am aware though that addressing this is a major issue for Graphisoft...

And now this latest bugbear is to do with the sun. Often I've had to 'cheat' with orientation to get all the views of a building I have look reasonable. In Artlantis it was a pain as I had to manually render the views (changing the sun each time) or set up multiple files and batch them....
I thought with 9 we could now define different sun conditions with different views and "automate" the whole thing. Even not changing the north point - just times, I am still finding the Lightworks objects are not reliably picking up the sun settings saved with a view...so now I am reverting to saving views with different layer combinations - and having the Lightworks sun&sky objects in different layers with different settings (manual of course)...seems unnecessarily complicated .....comments anyone?

And finally - what a shame we can't get scaled renderings of elevations ( a la ArtLantis) through the lightworks/ ArchiCAD combo...

BTW I will be VERY interested to read Dwights analysis of rendering - as to what is the most efficient / smooth workflow / rendering method with acceptable results....

Re: LightWorks Sun

Dwight — Mon, 04 Apr 2005 04:52:28 GMT

I will have three quality level observations, but won't be naming them after American haircut styles since I am advised that it won't play well in Gdansk.

It is unfortunate that the quality levels aren't uniform - ie - to get some of the better material effects, like mirror mapping, ALWAYS needs final setting. What were they thinking?

The sun/sky objects probably aren't updating because you need to rebuild the 3D model each time for it them to change, but:
I think your layer strategy is the best one under the circumstances.
I don't remember this as being a feature......

You CAN get scaled elevations, but only by calculated sizing with pixels, not by dialling in a scale.

No wonder the book is a month behind.

Re: LightWorks Sun

stefan — Mon, 04 Apr 2005 12:31:27 GMT

Isn't the explanation about "soft shadows" the difference between raytraced shadows (sharp) and mapped shadows (bitmaps, which can be potentially less sharp)?

In 3ds max or Cinema4D, a raytraced shadow gives a clean and sharp shadow, where a soft shadow is a greyscale image, rendered from the point of view from the lightsource. The "size" is the resolution (e.g. 250x250 pixels).

But you can obtain raytraced soft soft shadows too, by additional sampling and then some smoothing (basically using several lights instead of one, aka "area lights").

Not sure what it is that the LightWorks engine is using, but I never saw any soft shadow...

The Photoshop difference? Are you sure it is not just the difference with some automatic brightness levelling?

Re: LightWorks Sun

Dwight — Mon, 04 Apr 2005 16:49:03 GMT

Neither the built-in sun nor the sun object cast soft shadows.
The built-in sun has plenty of controls that have no effect. I am reminded of a 1960's Candid Camera eposide where they had the stooge trying to fill egg cartons with eggs arriving on a conveyor belt. They told him the buttons controlled the speed of the belt but they weren't connected and when the belt began to accelerate, there was a mess. Haha.
The sun object is a controlled number of lamps with no falloff that "converge" through some arbitrary point to approximate a soft shadow. My study shows six suns with convergence<.5 degree to be best, but it all depends on how diffuse you want the sky to become, since the sun doesn't cast a soft shadow in reality, only when its light rays are scattered by diffuse cloud. There is a problem resolviing material roughness with fewer than six suns where stucco-like materials created with the roughness shader get black spots. That's hard-earned experience talking, sonny. Solving these issues is taking more time than I figured, but we need to deliver a useful product...