You are not logged in.

Argh

Apprentice

(10)

  • "Argh" started this thread

Date of registration: Sep 5th 2003

Reputation modifier: 9

  • Send private message

member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month

21

Saturday, September 3rd 2005, 8:31am

<font size=1 face="trebuchet ms"><BLOCKQUOTE><hr size=1 noshade>Argh, could you give us an idea of what the difference is on the Oc between 0.000000-&gt;1.000000 and on the Ec between the three lines of 0.000000-&gt;1.000000? I´ve been playing with it, but I´m having a hard time seeing the difference if I pick a low number or a high number for each. Thanks! <hr size=1 noshade></BLOCKQUOTE></font><font face=´trebuchet ms, Verdana, Arial, Helvetica´ size=2> Oc stands for &quot;opacity channel&quot;. An Oc value of 1.000000 (remember folks, the number of zeroes is important) means that the object is not transparent at all. Lowering it towards 0.000000 gradually increases the transparency. Using this with a TGA file or DDS DXT3 file (both of these have their own alpha channels) requires some care, because it´s going to be hard to see what transparency is being caused by the alpha channel, and which by the opacity channel. Ec stands for &quot;emissive channel&quot;. &quot;Emissive&quot; texturemaps emit more &quot;light&quot; from each polygon than do normally-shaded polygons. Hence, since the FL engine doesn´t support emissive objects (a feature found in high-powered raytracers, not computer games at this time) we´re talking about a difference between the shading rate between polygons that are not being lit by other sources very strongly. In a perfectly-lit world (iow, where there´s a globe of RGB 255, 255, 255 light surrounding your object), emissive objects won´t seem to &quot;do anything&quot;, because everything is already lit to its maximum value. In anything less, the effects of Ec become more and more obvious. The reason why there are three values, instead of one, took me awhile to figure out... but here´s the scoop: these are RGB values! If you structure your Ec like so with an object that´s pure white, per its texture: 1.000000 0.000000 1.000000 ... and then put it into total darkness... then the object will be YELLOW, because color 255, 0, 255 is pure yellow! Now... that said, it´s not as easy to manipulate the Ec channels as one might expect. This is because the FL engine actually allows users to boost overall values past the &quot;pure white&quot; level... and doing so will cause an error to show up in Spew. This probably isn´t very harmful, and is probably just client-side... and I´ve never seen the engine crash because it happened... BUT... getting errors down to a bare minimum is a good idea. Short version: don´t use Ec values of 1.000000. Use a maximum of 0.800000, and you´re not likely to see the error show up in Spew... but the glowing effect will still be plenty strong, trust me <img src=smilies/icon_smile.gif width=15 height=15 border=0 align=middle>
Signature from »Argh«

Argh

Apprentice

(10)

  • "Argh" started this thread

Date of registration: Sep 5th 2003

Reputation modifier: 9

  • Send private message

member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month member since 180 month

22

Sunday, October 2nd 2005, 1:24am

<b>About the Freelancer Texture formats and File Types </b> Basically... FL uses <i>both </i> TARGA and DDS textures, for various things. TARGA (TGA) was the original format used for everything. I think that when the game was originally being built, DA was going to use 8-bit compressed TGAs for things like ships, and 32-bit TGA for things that needed a 16-bit alpha channel. But then DDS came along... DDS, which has the compression levels of JPG, but has native support for mipmapping and 8-bit alpha channels. Pretty darn good format... and DA went with it. The FL engine supports DDS DXT1 and DDS DXT3 formats. All FL Material nodes that actually make use of TARGA formats are listed as MIP0, MIP1, MIP2, etc., when you look at them in UTF Edit. If you look at some of the textures used for certain things where different mip levels was actually needed, DA used as many as 8 different mips. If a texture is listed as MIPS, however, then you´re looking at a DDS file. The two types of DDS both have advantages/disadvantages: DXT1 has the best quality and compression ratio. You can make 2048/2048 textures at about 1MB in size, if you leave out the mipmaps... try doing <i>that </i> with a 32-bit TGA! But... DXT1 does not support any alpha channel data, at all. DXT3 supports an 8-bit alpha channel. This is OK for things that are basically either clear... or opaque... but is crappy for things that require subtle amounts of transparency. However, it still has better compression than TGA by a long shot, and supports mipmaps. Basically... the <i>ONLY REASON </i> to use TGAs in your MATs... is if you have something that <i>absolutely requires </i> delicate transparency levels. IOW, use as infrequently as possible. If you want insane levels of detail... use DDS DXT1 !!! If you need a simple black/white alpha layer, use DDS DXT3. I´m adding this to my &quot;How to Skin&quot; Tutorial... and someday, somebody needs to alter Drizzt´s Tutorial, because neither he nor Kasdian really understood texture formats very well... nor how important they are to the overall final finish on a ship in the FL engine. Basically, folks... 95% of the time, you should have a final ship with ONE MATERIAL. One large texturemap is more efficient, come render time, than multiple smaller ones, even if the overall memory size is smaller! People get into the bad habit of using lots of small textures- when you can avoid it, do so- it will save a lot of FPS. And that texturemap, 95% of the time, can be DDS DXT1, no mipmaps... for maximum beauty, utility and efficiency <img src=smilies/icon_smile.gif width=15 height=15 border=0 align=middle>
Signature from »Argh«

Social bookmarks

Legend:

Forum contains no new posts
Forum contains new posts
Forum is closed
Forum is an external link