OK, let this cube be a room we want to make for Lightfeather.
Lucky you – default material also contains texture, so switch to Texture properties [F6] and rename texture also to “Walls”, then change type to Image, press Load button and load texture file (better use standard rectangular textures with size 128x128, 256x256, 128x512 etc., avoid nonstandard sizes).
If you think that you can right now see textured cube in Blender – you wrong. Don’t forget that primary goal of that fantastic software is Rendering. Not real-time rendering. For this we have to assign texture coordinates and switch to Textured shading, but first…
With those two faces selected press small button New for adding new material, then press Assign. But that’s not all. Next switch to Material properties again [F5] and click on small spin-button in the Material name, in popped menu select ADD NEW. Hm, newly created material have all the same properties.
You only need rename it to “FloorCeiling” for example and assign another texture. Do you think it’s easy? Don’t hurry – the texture you see in new material is linked to the first one, so if you change it, your walls also change their texture. You have to break this link (which also mean make single-user copy) by clicking the number button from right of the texture name:
Then rename the texture to “FloorCeiling” and load another texture file.
For better visual splitting you can also change colors of the materials – for example make walls brighter and floor/ceiling brownier. Press [F5] and return to material properties. Click on one of the color dockers and change colors. For switch to 1st material use small arrows near the material number:
Now press X to delete selected. The right answer is “Faces” btw.
Hm, it seems this column is too huge for such small room, eh? So select it again with [Alt] + clicking on any vertical edge, and scale it keeping Z coordinate unchanged (S; [Shift]+Z; [Ctrl] for snapping).
Now you have to check which material this column is assigned? By default it uses currently active material. If you want to add another material for columns – you are welcome. But I just leave it with my FloorCeiling.
Further I want to add another columns to this scene, just duplicating this one. Would be better to duplicate already UV-mapped columns, so keep it in mind. Right now you just move it a bit in X or Y direction so we could make duplication by rotating around center. Use those small RGB arrows for it. I personally move it in -Y direction by 2 snaps:
You can read this cool tutorial first if you wish: http://wiki.blender.org/index.php/Manual/Unwrapping_a_Mesh
or this for example: http://marginal.org.uk/x-planescenery/hangar_tutorial/3-textures.html
For easy navigating between UV-editor and 3D-view lets split current viewport into 2. Move your cursor to the bottom split-line:
Then press MMB and select Split areas, point in to the top view and press LMB to accept. Now select window type as UV/Image Editor:
If something is selected press A twice – this is for Select/Unselect all.
Let’s start from Walls – in Editing properties [F9] switch to 1st material “Walls” and press small Select button. Next select UV Face Select mode from drop-down menu:
Now in 3D-view press U and select Unwrap. Now look at the result in right viewport. This is how Blender tried to unwrap our walls onto UV-space. OK, at least he did it.
But this uv-mapping is not correct – the walls texture is bricks, and they should be tiled all over the walls. Press on spin-button on the bottom of the right viewport and select the walls texture file name – in my case this was brick.tga:
Wow, realtime rendering in Blender! Nice. But uv-mapping still wrong. You have to add a split, or so-called Seam, in the 4 walls so they could correctly unwrapped into the rectangle. For this simply hold down [Alt] and press edge of one corner with RMB. Repeat U->Unwrap and be happy with result:
For dynamic uv-map change in 3D-view in right viewport go to menu View->Update Automatically. You just have to scale a little bit the uv-map. While mouse is under right viewport press A for Select All (twice in case there were some selection – you’ll notice all pink points became yellow). Now as usual press S for scale and move mouse to get best results. You can also press G for moving the selected map. I prefer to make uv-map be scaled exactly to height of texture and positioned at center:
Ok, walls are ready, time to map floor and ceiling. Press [Tab] to enter Edit mode and press A to unselect all selected faces. Now simply pick on top and bottom faces and switch back to UV Face Select mode (you can press [Tab] again for that). That’s all – at right viewport you could see the square uv-map, that’s how Blender “unwraps” simple faces automaticaly. (Of couse if your room is not squared then to avoid texture distortion you could make simple project uv-coordinates from view by hand. In 3D-view press Numpad 7 to switch to Top view and press U->Project From View). If you want your texture tile – just scale your uv-map untill you satisfy.
Now again press small spin-button and change texture to floor/ceiling texture filename – in my case this is concrete.jpg:
(For fast maximazind/demaximazing Viewport use shortkey [Shift]+[Space]). Now you can rotate yor room in textured mode and observe the uv-mapping.
Don’t think that Blender uses double-sided rendering method – no, we just forget about normal flipping for the cube. So let’s flip them now.
Press [Tab] for Edit mode, while floor and ceiling still selected change material to Walls and press Select button (or you can select directly from view). Check that now all walls and floor with ceiling are selected at once. Note: column normals are ok, so don’t select it.
Now find small button “Flip Norm” in Mesh Tools palette:
One more to go: let’s unwrap the column. So while you are still in Editing mode let’s add split seam from here, and later use it for uv-unwrapping. Change selection mode to Edge selection ([Ctrl]+[Tab]->Edges or simply press the small line icon in bottom right corner of 3D-view), zoom view to look column closer and select one of the vertical edges with RMB. Next press [Ctrl]+E->Mark Seam:
Go back to Face selection mode. Finally select column with [Alt] + clicking on any vertical edge. Now go back to UV Face Select [Tab] and notice that now you can freely see the column (aha, wall normals are flipped!), and its still untextured, so let’s unwrap her.
Press U->Unwrap, and assign texture to uv-map – in my case it’s again concrete.jpg.
Hm, I don’t like my uv-map is scewed. So just box-select all top vertices (by pressing B and drawing virtual box with LMB), then move them a bit to the left. Scale and move whole uv-map if you wish. Now it’s perfect:
We finished with uv-mapping for textures. Next step will be making new uv-coordinates for lightmapping. But first lets duplicate the column so in future lightning became more interesting.
We have to delete the initial column with X now because it was duplicated also.
(For some odd reason by default newly added columns are not smooth, but I want all columns to be beautifully round, so please select all 4 columns, and press W->Set Smooth)
Press it and you’ve got second uv-map set. Rename it to Lightmap, and first one to Diffusemap if you wish. But this new uv-map is empty now, and I don’t think that repeat all same uv-operations from the beginning is the best way to fill it. So let’s make a trick. We’ll copy the room object and using special script copy uv-map from one object to another.
Switch to Object Mode. For copying the room – select it with RMB, press [Shift]+D, and move your cursor, LMB for accept. Now while second object still selected check that currently active is first uv-set with name Diffusemap. Next click on initial room with LMB to select it. Check that now active is Lightmap uv-set. Press [Shift] and click on copied room so now both object are selected, but second one is active. Next switch the right viewport to Scripts Window, and from menu select Scripts->Object->UV Copy from Active.
It’s done. Now select and delete that extra object with X.
Select the room and enter into Edit mode again with [Tab]. Select all faces with A and switch to UV Face Select mode. In right viewport from menu select Image->New… and set size to 1024x1024.
Rename the default Untitled to Lightmap. Now return to Edit mode [Tab] and deselect all with A. Now we will modify uv-sets, so first select Walls and switch back to UV Face Select [Tab]. Select all uv-coords by pressing A on right viewport. Now scale S and move G it so that it fits into our texture as follows (use [Shift]+[Space] to maximaze uv-window):
Next is FloorCeiling separatly this time – return to Edit mode and select top face. Switch back to UV-mode. Scale and move until it fit. Repeat for bottom face. Now if you select in Edit mode both walls and floor with ceiling then back in UV-mode you can see something like this:
Now columns. We have to select each column separatly, so in Edit mode switch to top view (Numpad 7) and use Box-select (B) of columns:
Scale and move each column so they fit in our Lightmap. My final map is looks like that:
It’s not perfect, and I’ve got a lot of unused space, but you’ve got the idea – now you can control all your lightmapping coordinates by hand (unlike in gile[s] or FSRAD for example).
Oh, I could eliminate a lot of unused space by using another texture size – 1024x512 for example. For this simply add another Image (rename it again to Lightmap), but Blender will scale the uv-map nonuniformly to fit this new size, so you have to scale it back. Use S for scale, press Y for scale in Y direction only, and press 2 as scale factor. Now its perfect:
Note: for correct export to Lightfeather of cylindrical (or any unwrapped) surfaces you have to keep in mind that split seams should be in same places for both uv-maps – Lightmaps and Diffusemaps.
Press [F5] to get light properties and increase light Energy to 2 for example.
Now change right viewport back to UV-window, in 3D-view select our room and press magic shortcut: [Ctrl]+[Alt]+B means Bake Selected Meshes->Full Render. After a while you could see something like that (if you switch rendering mode to Textured):
That’s close to what we’re waiting for except that diffuse textures are rendered also. So we have to switch them off for a while and also change material color to full white.
I found that Ambient Occlusion is not rendered because of size of our room – it's simply too small for default AO settings. To change them switch to Material properties [F5] and next to World properties (small button with blue globe). Change Dist to 0.10 and Energy to 0.50 or even less.
Switch to Material properties [F5] and uncheck the texture using box in Texture palette. Then change material color to full white. Make the same operation for second material also. Repeat [Ctrl]+[Alt]+B for Bake Selected Meshes. Ok, now it’s looks fine for lightmap:
You have to save this newly created image to disc and reassign it as a texture. Go to menu Image->Save As… and save it as Lightmap.tga for example. Next select next free texture slot below Walls (or FloorCeiling) and press small Add New button:
Go to Texture settings [F6] and change Texture name to Lightmap, type to Image and select Lightmap.tga as texture file (you can select it from small spin-button as it’s already loaded in Blender). Make same operations for second material.
Now invert texture switches to be on for Walls and FloorCeiling and off for Lightmap to export only diffuse textures this time, and switch the current uv-set to Diffusemap:
Export again but this time with name LFroom.obj.
newmtl Walls_brick.tga
Find similar material in file LFroom_lmap.mtl, in my case it was line:
newmtl Walls_Lightmap.tga
so we have to replace all occurencies of Walls_Lightmap.tga to Walls_brick.tga in both LFroom_lmap.mtl and LFroom_lmap.obj.
Repeat for second material.
modelconverter LFroom.obj LFroom.lfm LFroom -2nduvLFroom_lmap.obj
Now you can also tweak an exported LFroom.lfm a little bit. Open it in Notepad also and change all occurencies of lines:
feature=ERPF_LIGHTMAP
to
feature=ERPF_LIGHTMAP4 or feature=ERPF_LIGHTMAP2
and for some odd reason exported file have all ambient colors as pure black, so please change following lines:
ambient=0,0,0, 255
to
ambient=255,255,255, 255
Now you can open your lightmapped file in Lightfeather:
Note: because of different coordinate systemes between Blender and Lightfeather all exported files are mirrored. So if you want your geometry will be exactly the same prior exporting from Blender you must Mirror all your meshes with [Ctrl]+M->X Local. Then you have to flip all normals as well.
Happy modeling with Blender and happy playing with Lightfeather! Thank you.