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>Blender Documentation Volume I - User Guide: Last modified April 29 2004 S68</TH
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><A
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>&#60;&#60;&#60; Previous</A
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>Radiosity</TD
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><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="radiosity_juicy"
></A
>Radiosity Juicy example</H1
><P
>&#13;		To get definitely away from dry theory and shows what Radiosity Modelling
		can really achieve let's look at an example.
	</P
><P
>&#13;		This will actually show you a true Global Illumination scene, with smoother results
		than the 'Dupliverted Spot Lights' technique shown in the Lighting Chapter to attain
		something like <A
HREF="x8417.html#BSG.RAD.F.S68.501"
>Figure 11</A
>.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.501"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen21.png"></P
></DIV
><P
><B
>Figure 11. Radiosity rendered Cylon Raider.</B
></P
></DIV
><DIV
CLASS="section"
><H2
CLASS="section"
><A
NAME="AEN8427"
></A
>Setting up.</H2
><P
>&#13;		We have only two elements in the scene at start up: a Raider (if you remember some Sci-Fi Movie...) 
		and a camera. The Raider has the default grey material, except for the main cockpit 
		windows which are black. For this technique, we will not need any lamps.
	</P
><P
>&#13;		The first thing that we will want to add to the scene is a plane. 
		This plane will be used as the floor in our scene. Resize the plane as shown 
		in <A
HREF="x8417.html#BSG.RAD.F.S68.502"
>Figure 12</A
>  and place it just under the Raider. 
		Leave a little space between the plane and the Raider bottom. 
		This will give us a nice "floating" look.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.502"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen02.png"></P
></DIV
><P
><B
>Figure 12. Add a plane</B
></P
></DIV
><P
>&#13;		Next, you will want to give the plane a material and select a colour for it. 
		We will try to use a nice blue. You can use the setting in <A
HREF="x8417.html#BSG.RAD.F.S68.503"
>Figure 13</A
>  
		for it.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.503"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen03.png"></P
></DIV
><P
><B
>Figure 13. Plane colour</B
></P
></DIV
></DIV
><DIV
CLASS="section"
><H2
CLASS="section"
><A
NAME="AEN8444"
></A
>The Sky Dome</H2
><P
>&#13;		We want to make a GI rendering, so the next thing that we are going to 
		add is an icosphere. This sphere is going to be our light source instead 
		of the typical lamps. What we are going to do is use its faces as 
		<I
CLASS="emphasis"
>emitters</I
> that will project light for us in multiple 
		directions instead of in one direction as with a typical, single, lamp. 
		This will give us the desired effect.
	</P
><P
>&#13;		To set this up, add an icosphere with a subdivision of 3. 
		While still in EditMode, use the <B
CLASS="keycap"
>BKEY</B
> select mode
		to select the lower portion of the sphere and delete it. 
		This will leave us with our dome. 
		Resize the dome to better fit the scene and match it up with your plane. 
		It should resemble <A
HREF="x8417.html#BSG.RAD.F.S68.504"
>Figure 14</A
>.  
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.504"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen04.png"></P
></DIV
><P
><B
>Figure 14. Sky dome.</B
></P
></DIV
><P
>&#13;		Next, we want to make sure that we have all the vertices of the dome 
		selected and then click on the EditButtons (<B
CLASS="keycap"
>F9</B
>) 
		and select <TT
CLASS="literal"
>Draw Normals</TT
>. This allows us to see 
		in which direction the vertices are "emitting". 
		By default it will be outside, so hit the <TT
CLASS="literal"
>Flip Normals</TT
>
		button, which will change the vertex emitter from projecting outward 
		to projecting inward in our dome (<A
HREF="x8417.html#BSG.RAD.F.S68.505"
>Figure 15</A
>). 
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.505"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen05.png"></P
></DIV
><P
><B
>Figure 15. Sky dome.</B
></P
></DIV
><P
>&#13;		Now that we have created our dome, we need a new material. 
		When you create the material for the dome change the following settings in 
		the MaterialButtons (<B
CLASS="keycap"
>F5</B
>):
	</P
><P
><TT
CLASS="literal"
>Add</TT
> = 0.000</P
><P
><TT
CLASS="literal"
>Ref</TT
> = 1.000</P
><P
><TT
CLASS="literal"
>Alpha</TT
> = 1.000</P
><P
><TT
CLASS="literal"
>Emit</TT
> = 0.020</P
><P
>&#13;		The <TT
CLASS="literal"
>Emit</TT
> slider here is the key. 
		This setting controls the amount of light 
		"emitted" from our dome. 0.020 is a good default. Remember that the dome
		is the bigger part of the scene! you don't want too much light!
		But you can experiment with this setting to get different results. 
		The lower the setting here though the longer the "solve" time later.
		(<A
HREF="x8417.html#BSG.RAD.F.S68.506"
>Figure 16</A
>). 
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.506"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen06.png"></P
></DIV
><P
><B
>Figure 16. Sky dome material.</B
></P
></DIV
><P
>&#13;		At this point we have created everything that we need for our scene. 
		The next step will be to alter the dome and the plane from "double-sided" 
		to "single-sided". To achieve this, we will select the dome mesh 
		and then go back to the EditButtons (<B
CLASS="keycap"
>F9</B
>). 
		Click the <TT
CLASS="literal"
>Double Sided</TT
> button and turn it off
		(<A
HREF="x8417.html#BSG.RAD.F.S68.507"
>Figure 17</A
>).  Repeat this process for the Plane.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.507"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen07.png"></P
></DIV
><P
><B
>Figure 17. Setting Dome and plane 'single sided'.</B
></P
></DIV
></DIV
><DIV
CLASS="section"
><H2
CLASS="section"
><A
NAME="AEN8493"
></A
>The Radiosity solution</H2
><P
>&#13; 		Now the next few steps are the heart and soul of Global Illumination. 
		Go to side view with <B
CLASS="keycap"
>NUM 3</B
> and use <B
CLASS="keycap"
>AKEY</B
>
		to select all of the meshes in our scene. Next hold <B
CLASS="keycap"
>SHIFT</B
>
		and double click on your camera. We do not want this selected. 
		It should look similar to <A
HREF="x8417.html#BSG.RAD.F.S68.508"
>Figure 18</A
>.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.508"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen08.png"></P
></DIV
><P
><B
>Figure 18. Selecting all Meshes.</B
></P
></DIV
><P
>&#13;		After selecting the meshes, go to camera view with <B
CLASS="keycap"
>NUM 0</B
> 
		and then turn on shaded mode with <B
CLASS="keycap"
>ZKEY</B
> 
		so we can see inside our dome.
	</P
><P
>&#13;		Now select the Shading context (<B
CLASS="keycap"
>F5</B
>) and the Radiosity Buttons Sub-context <B
CLASS="guiicon"
>&#13;  		<IMG
SRC="PartR/radiosity/gfx/RadButton.png">
  		</B
>). in the <TT
CLASS="literal"
>Radio Tool</TT
> Panel, click the 
		<TT
CLASS="literal"
>Collect Meshes</TT
> button. You should notice a change 
		in your view in the colours. It should look similar to <A
HREF="x8417.html#BSG.RAD.F.S68.509"
>Figure 19</A
>.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.509"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen10.png"></P
></DIV
><P
><B
>Figure 19. Preparing the Radiosity solution.</B
></P
></DIV
><P
>&#13;		Next, to keep the Raider smooth like our original mesh, we will 
		want to change from <TT
CLASS="literal"
>Solid</TT
> to <TT
CLASS="literal"
>Gour</TT
>. 
		This will give our Raider its nice curves back, in the same way <TT
CLASS="literal"
>&#13;		Set Smooth</TT
> would in the EditButtons. You'll also need to 
		change the <TT
CLASS="literal"
>Max Subdiv Shoot</TT
> to 1
		(<A
HREF="x8417.html#BSG.RAD.F.S68.510"
>Figure 20</A
>). Do not forget this step!
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.510"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen11.png"></P
></DIV
><P
><B
>Figure 20. Radiosity settings.</B
></P
></DIV
><P
>&#13;		After you have set <TT
CLASS="literal"
>Gour</TT
> and <TT
CLASS="literal"
>Max Subdiv Shoot</TT
>, 
		click <TT
CLASS="literal"
>Go</TT
> and wait. Blender will then begin calculating the 
		emit part of the dome, going face by face, thus "solving" the render. 
		As it does this, you will see the scene change as more and more light is 
		added to the scene and the meshes are changed. You will also notice 
		that the cursor in Blender changes to a counter much like if it were an animation. 
		Let Blender run, solving the Radiosity problem.
	</P
><P
>&#13;		Letting Blender go to somewhere between 50-500 depending on the scene can do,
		for most cases. The solving time depends on you and how long you decide to let 
		it run... remember you can hit <B
CLASS="keycap"
>ESC</B
> at any time to stop the 
		process. This is an area that can be experimented with for different results. 
		This can take from 5 to 10 minutes and your system speed will also greatly 
		determine how long this process takes. <A
HREF="x8417.html#BSG.RAD.F.S68.511"
>Figure 21</A
> 
		is our Raider after 100 iterations.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.511"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen12.png"></P
></DIV
><P
><B
>Figure 21. Radiosity solution.</B
></P
></DIV
><P
>&#13;		After hitting the <B
CLASS="keycap"
>ESC</B
> key and stopping the solution,
		click <TT
CLASS="literal"
>Replace Meshes</TT
> (or<TT
CLASS="literal"
>Add New Meshes</TT
>)
 		and then <TT
CLASS="literal"
>Free Radio Data</TT
>. 
		This finalizes our solve and replaces our previous scene with the new 
		solved Radiosity scene. 
	</P
><DIV
CLASS="note"
><P
></P
><TABLE
CLASS="note"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="./stylesheet-images/note.gif"
HSPACE="5"
ALT="Note"></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>&#13;		Adidng rather than Replacing meshes is a form of Undo. You still have old
		meshes and you can re-run radiosity again! But you must move these new meshes to a new layer
		and hide the old layers before rendering!
	</P
></TD
></TR
></TABLE
></DIV
><P
>&#13;		Now we are ready for <B
CLASS="keycap"
>F12</B
> and render (<A
HREF="x8417.html#BSG.RAD.F.S68.512"
>Figure 22</A
>).
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.512"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen01.png"></P
></DIV
><P
><B
>Figure 22. Rendering of the radiosity solution.</B
></P
></DIV
></DIV
><DIV
CLASS="section"
><H2
CLASS="section"
><A
NAME="AEN8558"
></A
>Texturing</H2
><P
>&#13;		 There you go folks! You now have a very clean looking render with soft 360 degree 
		lighting using Radiosity. Very nice... But the next thing we want to do is add textures 
		to the mesh. So go back to our main screen area.
	</P
><P
>&#13;		Now try selecting your mesh and you will notice that it selects not only 
		the Raider but the plane and dome as well. That is because Radiosity
		created a new <I
CLASS="emphasis"
>single</I
> mesh through the solution process. 
		To add a texture though, we only want the Raider.
	</P
><P
>&#13;		So, select the mesh and then go into EditMode. In EditMode we can delete the dome and 
		plane since they are no longer needed. You can use the <B
CLASS="keycap"
>LKEY</B
> to 
		select the proper vertices and press <B
CLASS="keycap"
>XKEY</B
> to delete them. 
		Keep selecting and deleting until you are left with only the Raider. 
		It should look like in <A
HREF="x8417.html#BSG.RAD.F.S68.513"
>Figure 23</A
>.
		If we were to render it now with <B
CLASS="keycap"
>F12</B
>, we would get just a black 
		background and our Raider. This is nice... but again, we want textures!
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.513"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen14.png"></P
></DIV
><P
><B
>Figure 23. The Rider's mesh.</B
></P
></DIV
><P
>&#13;		To add textures to mesh, we must separate out the areas that we are 
		going to apply materials and textures to. For the Raider, We want
		to add textures to the wings and mid-section. To do this select 
		the Raider mesh, and go back into EditMode. Select a vertex near 
		the edge of the wing and then hit the <B
CLASS="keycap"
>LKEY</B
>
		to select linked vertices. Do the same on the other side. Next, 
		click on the mid section of the ship and do the same thing. 
		Select the areas shown in <A
HREF="x8417.html#BSG.RAD.F.S68.514"
>Figure 24</A
>.
		When you have those, hit the <B
CLASS="keycap"
>PKEY</B
> to separate the vertices selected. 
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.514"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen15.png"></P
></DIV
><P
><B
>Figure 24. Separating the Rider parts to be textured.</B
></P
></DIV
><P
>&#13;		We now have our wing section separate and are ready to add the materials 
		and textures. We want to create a new material for this mesh. To get a nice metallic 
		look, we can use the settings in <A
HREF="x8417.html#BSG.RAD.F.S68.515"
>Figure 25</A
>.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.515"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen16.png"></P
></DIV
><P
><B
>Figure 25. "Metallic" material.</B
></P
></DIV
><P
>&#13;		Time to add the textures. We want to achieve some pretty elaborate results.
		We will need two bump-maps to create grooves and two mask for 
		painting and 'decals'. There are hence four textures for the Raider 
		wings to be created, as shown in <A
HREF="x8417.html#BSG.RAD.F.S68.516"
>Figure 26</A
>.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.516"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/textures.png"></P
></DIV
><P
><B
>Figure 26. Four textures, from upper left corner, clockwise: RaiderBM, RaiderDI, Markings, Raider.</B
></P
></DIV
><P
>&#13;		The textures should be placed in four material channels
		in the rider top mesh. 'RaiderBM' and 'RaiderDI' should 
		be set to a negative <TT
CLASS="literal"
>NOR</TT
> 
		(<A
HREF="x8417.html#BSG.RAD.F.S68.517"
>Figure 27</A
>a -click <TT
CLASS="literal"
>NOR</TT
>
		twice, it will turn yellow). 'Raider' should be set up 
		as negative <TT
CLASS="literal"
>REF</TT
> (<A
HREF="x8417.html#BSG.RAD.F.S68.517"
>Figure 27</A
>b).
	</P
><DIV
CLASS="tip"
><P
></P
><TABLE
CLASS="tip"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="./stylesheet-images/tip.gif"
HSPACE="5"
ALT="Tip"></TD
><TH
ALIGN="LEFT"
VALIGN="CENTER"
><B
>Which material?</B
></TH
></TR
><TR
><TD
>&nbsp;</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>&#13;			A Mesh coming from a Radiosity solution typically has more than one
			material on it. It is important to operate on the right "original"
			material.
		</P
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.517"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen18.png"></P
></DIV
><P
><B
>Figure 27. Texture set-ups.</B
></P
></DIV
><P
>&#13;		The result is the desired metallic plating for the hull of 
		the Raider. Finally the fourth texture, 'Markings', is set to 
		<TT
CLASS="literal"
>COL</TT
> in the MaterialButtons 
		(<A
HREF="x8417.html#BSG.RAD.F.S68.517"
>Figure 27</A
>c). This will 
		give the Raider its proper striping and insignia. Our
		rider is quite flat, so the <TT
CLASS="literal"
>Flat</TT
>
		projection is adequate. Were it a more complex shape some UV mapping
		would have been required to attain good results. The 
		material preview for the mesh should look like <A
HREF="x8417.html#BSG.RAD.F.S68.518"
>Figure 28</A
>.
	</P
><DIV
CLASS="figure"
><A
NAME="BSG.RAD.F.S68.518"
></A
><DIV
CLASS="mediaobject"
><P
><IMG
SRC="PartR/radiosity/gfx/screen20.png"></P
></DIV
><P
><B
>Figure 28. Complete material preview.</B
></P
></DIV
><P
>&#13;	 	Our textures to <I
CLASS="emphasis"
>won't</I
> show up in the rendering right now 
		(except markings) because Nor and Ref type texture reacts to lighting, and there
		is no light source in the scene! Hence will now need to add a lamp or two, 
		keeping in mind that our ship is still lit pretty well from the Radiosity solve,
		so lamps energy should be quite weak. Once you have your lamps, you try a test 
		render. Experiment with the lamps until you get the results you like.
	</P
><P
>&#13;		The final rendering (<A
HREF="x8417.html#BSG.RAD.F.S68.501"
>Figure 11 in the Section called <I
>Radiosity Juicy example</I
></A
>) shows a nice 
		well lit Raider with soft texturing. 
	</P
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