Dave Donley's skydome

[mentalenergy]

thought i might start a new thread regarding the 'skydome' light mentioned in a recent thread about C4D. i followed daves instructions and the results are quite impressive. the first image below is a simple cube rendered with a regular directional light source:

now with the skydome light symbol:

even with such an elemntary model, you can see how much extra depth the image has... the object actually has some relationship with the ground other than a directional shadow!

2 main problems ive found with this however... first and foremost is rendering time: the first image rendered for me on an athlon700 in about 3 seconds... the 2nd image took about 10. with a more complex model rendering times really blow out (mind you, my skydome symbol has about 140 lights in it ).

in the rendering of an unfinished model below, you can see how soft shadows appear beneath objects as well as in between wall junctions, roof/wall junctions, etc, which improves image realism imensely. ignore the silly trees, theyre just there to illustrate a point below

my second complaint though would be that so many light sources generating so many shadows causes some unwanted effects... look at the walls especially on the left... theyre supposed to be plain white! that 'dirty' look is not a texture, its shadows from the tree model. is there any way of preventing this?

i wonder if it would work if an inverted version of this light symbol was made to place inside a model... i havent tried it yet but it would be great to get the same sort of depth inside too

[nic]

nice post.

i can't offer any help but i've been wanting to know for a while about the white-texture always being grey thing, unless you have lights shining directly onto the surface which eliminates all other shadowy effects. i dont know...white buildings, even with shadows, in real life, dont seem to appear grey.

[Yovav]

Metalist, maybe skydome can improve some current renderings but I don't think it is a true solution. Rendering is not only about quality, speed is a crucial factor.

I tried using the sky dome in the past, it really gives neat effects but the time loss is huge.

Much better solution is improving the rendering engine. RenderWorks Improved dramatically over the last years but still have way to go. I'm not a programmer but to my understanding, based on the information provided by Lightwork site (the guys who develop the rendering engine that RW uses), an improvement in the rendering quality is easy to implement. Since their technology is scalable and modular, we can get better results if Nemetschek will add the relevant Lightwork elements to RW. Of course the trade of will be higher price for RenderWorks.

I think that the most important question is "where to stop?". What kind of rendering quality most of RW users need, and willing to pay for. My view is - "give us radiosity, and finish the dilemma - to export on not export". But it would be interesting to hear what other users think.

Two relevant links to this subject are: the discussion in this board titled "Altivec for lightwork"http://techboard.nemetschek.net/ubb/ultimatebb.php?ubb=get_topic;f=17;t=000316. And the lightwork site, that shows some beautiful examples of Lightwork engine capabilities: http://www.lightwork.com/lw_home.htm

[Cloud Hidden]

The skydome creates equal brightness from all the lights. What settings have worked best for y'all for the skydome versus the main directional light--the "sun"? 50 for sky, 100 for sun becomes too bright. 50/50? 75/75? I'm experimenting, but maybe there's a good rule of thumb running around out there...