Black Sky rendering issues

[SpookyChick]

Ok. still fairly new to Twilight, just got a new PC (3.06 GHz) and still having difficulty doing the renders I need to for the projects I am working on (Sci-Fi illustrations). I need to be able to render things with a very bright, harsh light, deep sharp-edged shadows and a black sky. How do I do this, or is the capability even in Twilight? (I have read the manual / tutorial, and unfortunately, it didn't provide an answer) I ask because I realize a lot of sketchup and rendering progs are optimized for architecture, and I admit I am in kind of an odd niche doing illustrations and models for military sci-fi stuff.
Thanks in advance for any help. Aside from this little puzzle, I love TwilightRender and when I can afford to in a few months, I will do something I almost never do and buy the full version of Twilight(Render, that is. Death to sparkly Vampires!)

[Fletch]

Love your screen name.

To use a black sky for rendering you have many options.
Set the "Sky Color" to black, or almost black.
Set the Sky to "Spherical Sky" and load any spherical sky image you have found, such as a starry space sky, etc.
Or set the Sky "Background Color" to black.

Increase the power of the sky, or of the sun to modify their brightness.

Finally, on the camera tab, use the exposure and gamma controls to go as bright or deep as you want to go.

[SpookyChick]

Thanks. X-Files fan...What can I say?

Set the "Sky Color" to black, or almost black.
Set the Sky to "Spherical Sky" and load any spherical sky image you have found, such as a starry space sky, etc.
Or set the Sky "Background Color" to black.

Increase the power of the sky, or of the sun to modify their brightness.

Finally, on the camera tab, use the exposure and gamma controls to go as bright or deep as you want to go.

I've tried these options. Unfortunately there seems to be a problem with the illumination (or lack thereof, more to the point) when I set skycolor, or background color to black. Basically, the whole model shows up black, with no shadows, no light areas, etc. Exposure and gamma controls haven't seemed to do me much good, either, as the background ends up lightening or darkening along with the model. I'm pretty sure that this is stemming from something I am doing wrong; I just for the life of me can't figure out what it is that I'm doing wrong. Anyway, if someone can help me get over this case of Cranio-Rectal Implantation I've got myself in, I will be very grateful.
Oh, and I do very much thank you for the prompt response, Fletch. I'm so far behind schedule, I'm early for my next project. I'll probably be back in 8 hours or so. Time to get some sleep. :snores:

[Fletch]

Real-world scale is important... so if you are rendering something massively large, like a spaceship, and have only one tiny light, well, there's a problem.
Please post a simple scene demonstrating your issue, and we can "fix" it easily for you to see how it's done.

I'm attaching a large (sorry for the ugly) object scene with dark sky and harsh light as you've described, hope it can help?

[Fletch]

Here's same scene, different settings... playing with dusty sky setting and sky brightness.
This provided a nice red "fill" glow coming from the sky on the right. same settings and different times of day will be interesting as well.
The Physical Sky is powerful, and probably very under-explored by most Twilighters.
Sci-fi creators may find it quite useful.

[SpookyChick]

Ok, Thanks Fletch. The scene you posted illustrates the kind of lighting effects I am looking for, but I need sharper shadows, and for some reason, Light intensity just doesn't seem to make a difference. I will happily post a scene for you. Do you want the .skp, or just one of the completed renders? The lighting I am using is just sunlight and shadow effects, plus the "laser beams" ( I know, not visible in vacuum, but the client insists on them). I would love to know the exact settings you used in your test case, as those results are a lot closer to what I am looking for, even if the shadows are way more difuse than I was looking for. Is there a way to post images without hosting them on a public accessible source like flickr?

Late Update: I have yet to try it with the model I am working on, but in playing with the test model you sent, I found settings that give me (mostly) the kind of effects I was looking for. I will post further info soon. Thanks a bunch!

[Fletch]

Open the Light Dialog.
The sun slider is set to 7 in my scenes, slide it to zero for sharp shadows, or uncheck the 'soft shadow' box.

[SpookyChick]

Yeah, thanks. Definitely getting good results with your model, not so good with my own, and occasionaly running into instability issues, such as the entire background going neon green, and the model acquiring a green cast. I have run the plugin 'stray lines', as well as cleaning up all extraneous geometry. The only things I can figure at this point is that the ^$$$*!@#$@%!!!!!!! "laser beams" are screwing things up (being light emitters) so I am going to try it with out those, later tonight. Either that or it may have something to do with the model being almost entirely curved, reflective (polished metal) surfaces.

How do I attach files to my posts? The FAQ said to ask an admin or a mod, so I'm asking. Once I can do that I will happily provide either a pic of my renders and/or the model.

This is the last time I ever take a Star Wars related commission.....

[Fletch]

Learning any new program is frustrating... calm is advised.

Below my text box as I type on the forum is a tab called "options" and a tab called "upload attachment".
Do you not have these options?
You may need a few posts before you are allowed to upload the attachment...
meanwhile, box.net or yousendit.com are good file sharing sites.

[Fletch]

if the "laser beams" are light emitting surfaces, then you should set them in the template to be "Fake" emitters... this will render instantaneously in comparison to actual emitters when using Easy 1-7 render settings... and use much less RAM.

Easy 09 is the best render setting for complex scenes with lots of light, and metal, and reflections.