What do you mean, "centered to the scene"? DirectonalLight3D has internally always worked the same. But in previous versions, it's position was used to calculate the direction, which was essentially just the inverse of the position vector relative to the scene origin (e.g. if it was above your scene origin, light would be downward from infinitely far away).
The position properties might have seemed logical when one incorrectly thinks of the dir light as a point light, but it's not and doesn't work like one. Instead, this caused a huge logical issue: If you "positioned" a dir light between two objects, it would still light both of them from the same direction, because it's considered to really be infinitely far away. This was and is correct, but could be extremely hard to grasp, since the existence of position attributes implied that the light had a position, when in fact it was just a result of it extending Object3D. So the position properties were removed. If you want to simulate zenith sun, use a direction vector of (0, -1, 0) i.e. downward. To have a western sunset, use (1, 0, 0) i.e eastward pointing. Hope this helps you guys understand the concept behind the light source. :) Cheers /R On Jun 7, 11:32 am, Michael Iv <[email protected]> wrote: > Got you David , it is like a Sun Light actually but directed . Still , it is > hard to implement it on objects centered to the scene > > On Mon, Jun 7, 2010 at 12:11 PM, David Lenaerts > <[email protected]>wrote: > > > > > > > Dot3 only supports directional lights, since the nature of directionals > > offer it a very fast way to calculate lighting. > > > Now, as for why the directional light doesn't have a position: don't > > consider it as a specific light source. Instead, it's typically used for a > > strong light source very far away, such as the sun. Of course, it's an > > approximation, but again it offers optimizations. The idea is that wherever > > you are in the scene, the light always comes from the same direction (hence > > the name). If it were to have a position, then the light direction would > > change depending on where the lit object is relative to the light (and that > > is a point light). > > > Hope that clarifies a thing or two! > > > David > > > On Mon, Jun 7, 2010 at 10:50 AM, Michael Iv <[email protected]> wrote: > > >> I did it with PhongColorMaterial actually . Don't know why it doesn't work > >> with Dot3 I will try to check it too. > > >> On Mon, Jun 7, 2010 at 11:47 AM, Josh <[email protected]>wrote: > > >>> I'm having the same problem Michael, however I can't seem to get the > >>> PointLight3D to work with Dot3BitmapMaterials. does anyone know if > >>> Dot3s support pointLights? > > >>> On Jun 7, 8:44 am, Michael Iv <[email protected]> wrote: > >>> > It is hard to understand why directional lights position doesn't make > >>> sense > >>> > . I mean , take 3d modelling program ,or UDK or Unity(ok that is not > >>> the > >>> > same in terms of technology ) , but the light should have emission > >>> source > >>> > and the soruce should have a position in 3d space ? . and the source > >>> > position of DirectionalLight3D is in the center of the scene, So if my > >>> > object is not offset from the center ,there is a problem , the object > >>> > doesn't receive the light at all . And .direction doesn't help in this > >>> case, > >>> > I was trying to tweak it too without much success . Eventually used > >>> > PointLight3d. > > >>> > On Mon, Jun 7, 2010 at 10:35 AM, richardolsson <[email protected]> > >>> wrote: > >>> > > The direction property is the way to go. As of 3.5, directional > >>> lights > >>> > > don't have positions, which never made sense anyway since dir lights > >>> > > are orthographic in a way, and not to be considered as point in space > >>> > > -- they are infinitely far away. > > >>> > > If you cannot get direction to work like below, make sure you are > >>> > > using materials that support dir lights! > > >>> > > var light : DirectionalLight3D = new DirectionalLight3D; > >>> > > light.direction = new Number3D(0, -1, 0); // Downward > > >>> > > Cheers > >>> > > /R > > >>> > > On Jun 5, 10:15 pm, fab4ce <[email protected]> wrote: > >>> > > > Hi Fabrice, > > >>> > > > PointLight3D has a position property, but DirectionalLight3D > >>> doesn´t > >>> > > > have it. > > >>> > > > On 5 Jun., 19:53, Fabrice3D <[email protected]> wrote: > > >>> > > > > there is a position property > > >>> > > > > Fabrice > >>> > > > > On Jun 5, 2010, at 2:08 AM, fab4ce wrote: > > >>> > > > > > Hi all, > >>> > > > > > after updating to the new version 3.5 i had to change my > >>> directional > >>> > > > > > light from view.scene.addChild(light) to > >>> view.scene.addLight(light); > >>> > > > > > How can change my code for positioning the light in the scene? > >>> I was > >>> > > > > > using the .x and .y and .z properties of the light object. > > >>> > -- > >>> > Michael Ivanov ,Programmer > >>> > Neurotech Solutions Ltd. > >>> > Flex|Air > >>> |3D|Unity|www.neurotechresearch.comhttp://blog.alladvanced.nethttp:// > >>>www.meetup.com/GO3D-Games-Opensource-3D/ > > >>> Tel:054-4962254begin_of_the_skype_highlighting 054-4962254 > >>> end_of_the_skype_highlighting > >>> > [email protected] > >>> > [email protected] > > >> -- > >> Michael Ivanov ,Programmer > >> Neurotech Solutions Ltd. > >> Flex|Air |3D|Unity| > >>www.neurotechresearch.com > >>http://blog.alladvanced.net > >>http://www.meetup.com/GO3D-Games-Opensource-3D/ > >> Tel:054-4962254 > >> [email protected] > >> [email protected] > > > -- > >http://www.derschmale.com > > -- > Michael Ivanov ,Programmer > Neurotech Solutions Ltd. > Flex|Air > |3D|Unity|www.neurotechresearch.comhttp://blog.alladvanced.nethttp://www.meetup.com/GO3D-Games-Opensource-3D/ > Tel:054-4962254 > [email protected] > [email protected]
