|
|
light and workspace
About Truespace Archives
These pages are a copy of the official truespace forums prior to their removal somewhere around 2011.
They are retained here for archive purposes only.
light and workspace // Archive: Tech Forum
Post by rjeff // Feb 10, 2008, 5:03pm
|
rjeff
Total Posts: 1260
|
Ok I want a bright "sun" light to light the scene and I did find the area light, however when I turn shadows on..no shadows..see image. Sorry for the small image..but that is all I can show...but there is suppose to shadows off the columns. |
Post by johnhoward // Feb 10, 2008, 8:20pm
|
johnhoward
Total Posts: 231
|
Here's my method to get real-looking sunlight:
Use a directional light - move it up, about 3 times as high as highest object in scene.
In its settings panel,
under default, set size at 100 (for starters)
enable shadows and zero out the 4 numbers above the enable shadows checkbox (ATT settings) - experiment with color, perhaps slight yellowish
then, under "advanced", set map size at 4096
for shadow fill, use one ambiant, perhaps with a bluish color, or use other shadowless soft blue lights - best is Vray global illumination using a blue sky photo
for careful aiming, I go to Model side, use the link editor to select the directional light (once it's up high, it's a bit hard to find for selecting), make it the view camera, then select an object in the scene and navigate around looking at the subject from the point of view of the light. (I hope they move that feature over to workspace). |
Post by kena // Feb 10, 2008, 9:04pm
|
kena
Total Posts: 2321
|
For a warmer sunnier light, make the color slightly more orange.. It si always better to err toward the warmer side fo yellow to get a good color. |
Post by rjeff // Feb 11, 2008, 4:15am
|
rjeff
Total Posts: 1260
|
Thanks for all the help guys..but the qustion still remains..why does that area light not cast shadows..when I have shadows turned on. |
Post by Steinie // Feb 11, 2008, 5:12am
|
Steinie
Total Posts: 3667
|
Is this realtime or offline? Realtime only Omni and Spot have shadows. |
Post by TomG // Feb 11, 2008, 5:30am
|
TomG
Total Posts: 3397
|
I'd have to see the scene and its layout, as to where the area light is, where the geometry is etc. Also yes, what render engine, and if model or workspace side used to add the lights.
Some screenshots of that might help. Be sure to check that shadows are on for the area light. Check if raytraced or mapped are being used (try the other). Check that raytracing is on if using raytraced shadows. Check that the objects are not set to disable shadow casting or receiving.
HTH!
Tom |
Post by johnhoward // Feb 11, 2008, 6:46am
|
johnhoward
Total Posts: 231
|
Directional lights also have real-time shadows. |
Post by johnhoward // Feb 11, 2008, 7:09am
|
johnhoward
Total Posts: 231
|
I also cannot get the area light to throw a shadow in realtime - it does produce a grainy one when Vray rendered.
My guess is that this is another result of Global Warming which is caused by free markets. The consensus is that socialism would cast shadows. |
Post by TomG // Feb 11, 2008, 8:01am
|
TomG
Total Posts: 3397
|
An area light should not cast shadows in real-time, if I remember rightly. Only spots and directional have shadows.
The shadows in a workspace Area Light are for V-Ray, and can be adjusted using the Area Samples. It will act like a shadow casting omni light as far as Lightworks is concerned - there will be no soft shadow effect from it.
A Model side Area Light is a different beast, and will create soft shadows in Lightworks and V-Ray.
But neither kind will cast shadows in real-time.
HTH!
Tom |
Post by prodigy // Feb 11, 2008, 8:31am
|
prodigy
Total Posts: 3029
|
"An area light should not cast shadows in real-time"
Yes Tom, Area doesn't cast shadows in realtime. |
Post by rjeff // Feb 11, 2008, 9:21am
|
rjeff
Total Posts: 1260
|
now see that make no sense.. I can't get the amount of light I need from the other lights...and to be honest I hate the way WS does the light adjustment. Why don't just have a slider that goes from dim to bright..not the crap where you have to ajdust it down to make it bright..that makes no sense..who progamed the lights in WS monkeys...sorry had to rant. In my opinion all lights should make shadows..and LW light adjusment box surpases WS light adjustment box.
that was pretty funny johnhoward...hehe got a chuckle out of that. |
Post by prodigy // Feb 11, 2008, 9:40am
|
prodigy
Total Posts: 3029
|
LOL.. I suggest check this links.
All in 1 - 1.1(Prodigy) (http://forums1.caligari.com/truespace/showthread.php?t=4929)
SpotLight (http://forums1.caligari.com/truespace/showthread.php?t=4871) (TrueBlue)
Infinite Lights (TrueBlue) (http://forums1.caligari.com/truespace/showthread.php?t=4742)
AreaLight (Prodigy) (http://forums1.caligari.com/truespace/showthread.php?t=4860) |
Post by TomG // Feb 11, 2008, 9:56am
|
TomG
Total Posts: 3397
|
Casting shadows in an offline renderer is not a problem, raytracing is always there to solve that :)
However its not as simple in real-time. The computations for different light types are different, and so its not as trivial as it might seem to say "Well Light Type One casts shadows, so why doesn't Light Type Three?".
Casting real-time shadows is in fact quite tricky (well it is if you want to keep performance, and give soft shadowing, etc). So some light types which are particularly designed for offline engines do need a real-time representation, but may not be able to give real-time shadows.
Prodigy has pointed to several existing user built components that address a set of different needs. This is a good way forward, to take the fundamental light types and construct new ones out of those that will meet particular needs.
In the case of the inbuilt Area Light, it really is a V-Ray light that has a real-time representation that lets you work with it to set it up without only seeing it in test renders. But other light types built from the fundamental real-time types should be able to meet your needs!
HTH!
Tom |
Post by rjeff // Feb 11, 2008, 10:29am
|
rjeff
Total Posts: 1260
|
Well thanks for all the help. I should say that I am not looking to render the image in vray or anyother render. I want it all realtime so I can do a walk through and see how intense the polys are on a system for some real time uses. That is why I need shadows so I can see how it taxes a system in real time. |
Post by prodigy // Feb 11, 2008, 11:54am
|
prodigy
Total Posts: 3029
|
Use spot light for that.. if you put a spot light far enough from your scene you can simulate sun and such..
To take in mind what can you do with few spot lights.. if you put enough spotlights surrounding your scene pointing to the center you can get something like GI on realtime..
I suggest play with it..
Augusto |
Post by rjeff // Feb 11, 2008, 12:41pm
|
rjeff
Total Posts: 1260
|
Thanks Prodigy will do that. |
Post by trueBlue // Feb 11, 2008, 1:08pm
|
trueBlue
Total Posts: 1761
|
Workspace Projector lights produce shadows too. |
Post by rjeff // Feb 11, 2008, 1:20pm
|
rjeff
Total Posts: 1260
|
hmm did the spots no shadows..I guess it will only render them..I need real time. |
Post by rjeff // Feb 11, 2008, 1:35pm
|
rjeff
Total Posts: 1260
|
well John i did what you said, and everything seemed to work ok with the exception of I could not chage the color, nor did I see the advacned tab you refered to. |
Post by johnhoward // Feb 11, 2008, 2:58pm
|
johnhoward
Total Posts: 231
|
For the advanced tab, look on the upper right side of the "Directional Light" panel where it says "default". Click and hold "default" and you will see "advanced". We hope.
But while you are still in the "default" you should see the color block. Simply double click on it and you should open the color-selection window.
On the 'Map size' under the 'Advanced' tab, 4096 is the max, giving the sharpest edges to the shadows (most like actual sunlight). You can experiment with lower numbers to get softer edges. |
Post by rjeff // Feb 11, 2008, 6:36pm
|
rjeff
Total Posts: 1260
|
thanks...I tried the color light last time to no avail..but I will try again |
Post by TomG // Feb 12, 2008, 5:36am
|
TomG
Total Posts: 3397
|
Hi rjeff,
Spots will most definitely cast shadows in real-time :) Be sure to add the spotlight from the workspace side and not from the Model side.
Start with a test scene, just a cube and a plane and one spotlight, and ensure you are getting shadows. Always good to start simple when diagnosing a problem :) Note that shadows are not on by default with the spotlight, you have to switch them on with the checkbox.
Let us know how that works and we can proceed from there!
And yes, the projector light! Very nice for all sorts of interesting effects - try it with a stained glass window image, or with a pattern of light and dark for the shadows of leaves from a tree, etc. Had forgotten about that one :)
Thanks!
Tom |
Post by W!ZARD // Feb 13, 2008, 3:12am
|
W!ZARD
Total Posts: 2603
|
Howdy - Workspace lights are not the most intuitive to use because we are accustomed to lights in renderers where if you want more light you make the light source brighter - like plugging in a higher wattage bulb.
Real time lights have an intensity factor (controlled by the colour intensity) but additionally they factor in attenuation which is the loss of amplitude (or brightness) over distance and so it relates more accurately to the real world.
A 100 watt bulb is still as intense at the bulb no matter the weather conditions - as the light ray travels further from the source however it loses strength, which has more to do with the medium the light ray travels through. Very clear air has low attenuation and does not decrease the brightness over distance. Hazy air has higher attenuation, foggy air higher attenuation again and smokey air even higher attenuation - or loss of brightness over distance and making the light source look dimmer even though it's real intgensity does not change. At least that's how I think of it and it seems to make sense!
Below is a pic of a massive scene - the scene file weighs in at 45.11 MB - using some big texture files. As you can see the shadows look pretty good andlook just as good closer. I've used an ambient light for the fill in and a directional light with shadows enabled, to represent the sun. It's a strain on my graphics card which has 256 MB of RAM - and sometimes the scene won't load unless I ensure I've emptied my swap files. But when it does load it looks pretty good - you can roam around in FP mode over the bridges and up the stairs in the right hand tower and so on.
Obviously a lot will depend on the scale of your scene, type of Graphics Processing Unit you have, sixe of shadow maps and textures etc. This scene bogs down if I use anti-aliasing, bloom or supersampling but I can compose a picture in the scene, bump all the quallity settings to max and it takes about 4 seconds to render a 1600x1200 picture.
I've included a screen grab showing the light settings I have - they may give you a starting point anyway. I recommend using smaller shadow maps to get things looking ok and then upping the shadow map size when you've positione your light.
Note that, for the sun directional lights are probably better - the light rays from a spot light spread out from a point source but the light rays in a directional light are parallel to each other
Hope this helps. |
|
