Kwakkelde Kwak

Are you sure you're looking at triangle numbers in SL? 3 boxes have 3x4x6 = 72 vertices in SL. In Maya they would have 3x8=24 vertices.

If it's a skybox and you don't need to do the wall with windows... i'd use three materials and just a planar UV map for each, covering the entire canvas.

Everything needs UV mapping, doesn't matter if it's small, big, just a few things or a whole bunch. When baking lights, also make sure your UV islands don't overlap anywhere.

Eric Boccara wrote: Like this talentless store https://marketplace.secondlife.com/stores/41755 A dead link, priceless.

Eh it was just an example Masami, to illustrate the "grid option" 2x2 is nice though, because you do not need to calculate anything, if x has a 12.34953 repeat, so does y. Again not rocketscience to make the y repeat 3 times bigger than x ofcourse, but an extra step for a potential buyer nonetheless. For a brick wall you don't even need to use the "grid option". You could place the islands side by side and push them against eachother wasting even less. But even then you are leaving valuable UV space unused for the lightmap, especially when the wall varies a lot in height. I'm just trying to grasp why LL doesn't want the lightmap because it would need its own UV map. Personally I'd say include it, in a lot of cases it would work just fine.

This? Mesh/Texture-refusing-to-be-applied-correctly

Yes getting the textures to align isn't that difficult for a diffuse map, but... Since you can't stack any UV space, you're very limited to how you can use the canvas. An example with three adjacent brick walls of different size. I don't think that's a very uncommon setup. In the top picture I set the texture repeat to 2x2, this means you can use a texture repeat of 2x2, 2x4, 4x2, 4x4 etc. To line up the three walls, the left lower corner of the wall needs to be on the left lower corner of the texture, or you will get half bricks in the corner when you start tiling. Also the dimensions in model space and UV space need to match. So the biggest wall can be scaled to fit within a quarter of the UV space. The two smaller walls are..well smaller. For diffuse mapping this is not a problem, since it's set up for tiling, but look at the enormous amount of unused UV space, space that can't be used for baking light. If you can use two UV maps however, you can stack the three walls, which is a little less work than the way it's done above. The big difference is, you can randomly place the walls on the canvas of the second UV for light baking. I admit it's not the prettiest of UV maps, but it's a lot more efficient than the one above.

Yes you're right, forget that last post. That's not what I ment in the post prior to that though. What I ment was with a UV map like in my example, you can have the single lightmap for everything in a 1x1 repeat, that will fit nicely. The problem will occur where the walls meet. Matching the diffuse map in the corners when you tile can be real tricky. The UV for the lightmap can be placed any way you want, but if you do that more or less randomly, like in the UV map I made, the diffuse map doesn't match. This problem will get worse when you start tiling the diffuse map. There's no problem when the wall has a stucco texture, but with bricks or bigger tiles, even in the best case only some repeats will work. You can't offset per face since that would affect all faces. So you'd have to use a lot of different faces and with only 8 per object. That can be a true pain. The other option would be to map out the walls on the UV on a grid, that's what I ment by some serious UV mapping. I agree it's not rocket science, but it takes some careful planning or it could result in big patches of unused texture space for the lightmap. (Not a real issue if this is limited to let's say 256 or 512)

Masami Kuramoto wrote: Baking shadows is not rocket science. Many SL creators already do it, and they know that it usually takes a non-overlapping UV layout. This feature, if added, will not raise the bar at all. No, baking shadows is not rocket science, but you can stack a texture once baked.

Masami Kuramoto wrote: Whenever you can stack, you can tile as well. It just takes a separate material/face. And sometimes some serious mindboggling UV mapping and tiling/offsetting, things can be a lot more complex than a four wall room. You could keep that pretty simple if you used a new material for every face you'd normally stack, but then 8 materials are a real limitation. I see more benefits than drawbacks really, but I'm not so sure if this is the case for the average user. Don't forget not everyone can use a 3d program like you can. One of the nicest features of SL is still the "do anything you please" environment. When things get so complicated only experienced builders can use new features, SL loses what sets it apart.

That error occurs in the free version I think, I see it all the time and it doesn't affect anything. I use 3DS Max 2013 Design with the SLAV 2012 script. You could ofcourse email or IM the creator of the script, Wiz Daxter.

I suspected as much going by the fact you kudoed Drongle, thanks for verifying though!

Drongle McMahon wrote: In the exceptional case, we get the savings Masami pointed out.... tiny dsn and light maps instead of huge baked map. I don't think those cases are so exceptional. As far as I can think of, the vast majority of builds in SL can either be mapped like in my example above OR there is no tiling/overlapping at all like in clothing. In both cases a single UV can be used for a high res (either by size or by tiling) diffuse map and a low res light map.

What exporter are you using? I know with 3ds max you'll get UV issues when using opencollada. With the autodesk exporter everything works just fine.

Masami Kuramoto wrote: All these things would work just fine with a single non-overlapping UV layout. As far as I can see there shouldn't be a problem with one UV for both lightmap and diffuse map. I made a simple room with four walls, two randomly placed columns and a light. The four walls have one UV map. If one wants to use 4 different diffuse maps for the 4 walls, their UV maps would be a part of this particular UV map. So material 1's UV would cover "face 1", material 2 "face 2" etc. The only small catch is one might have a hard time lining up the textures, a 1x1 repeat in SL won't show the entire texture applied. In this case that's easily fixed though, all 4 faces can go side by side on the UV map. EDIT... This ofcourse only works if you can do the UV mapping yourself. On sculpties or on SL prims you won't be able to do that. Maybe that's what was referred to.

Masami Kuramoto wrote: For better or worse. I'll adept I think, even the way it is proposed right now means a great improvement. __ So what should be possible with three textures is this I guess: 1 High: RGB Diffuse, A transparency (like we have now) 2 High: RGB Normal, A Specular 3 Low: R Light, A Emission/Glow Where "high" would have a max of 1024 and "low" either 512 or even 256. The third map even has two spare channels and like you pointed out earlier, the B channel of the second map could be used for something else aswell. You could put the emission/glow in the second texture and use RGB of the third for color intensity or something. The second texture could also be 512 I think, clothes textures shouldn't be more than 512 and for brick walls for example you could use a 2x2 or higher repeat in normals to match a 1x1 diffuse map. It should be possible to have different offsets and repeats for different channels within one texture. I was also wondering if it would be possible to have "the system" read one of the channels and use a resolution one step lower than the entire map. If that's the case, two textures would be enough for everything LL wants to implement. The emission/glow could go on the B channel of the normal map at a lower resolution. One huge drawback in using all these seperate channels is ofcourse Blender/3ds max/Maya etc do not produce these maps by default. I can see how seperate textures are easier to work with, especially with different sizes. That must have been a reason to propose it the way they did.

Knutz Scorpio wrote: With the Linden Home you get the house PLUS 117 prims, any where else and everything counts against your prim allowance including the house. Ah I didn't know that, never owned a Linden Home. Still a basic house can be very low prim so you'd have let's say close to 100 prims you can use the way you want.

Mathematical laws didn't change since then, so it should have been possible back then aswell. I can understand the decision was made back then, for some reason, to use all three channels though. I suspect it's because the calculation is faster using the z component instead of calculating the two possible z's then discarding one of them. Afterall the blue channel is already there for use. No point in overthinking this, we'll have to work with what SL swallows anyway.

Masami Kuramoto wrote: Object and world space normal maps actually need the third component. Well the question remains. As you said yourself, with an x and y (or red and green) plus the set length of the normal, the third component is not needed to calculate the vector. There are only two values possible for z (or blue) and one of them returns a negative normal so that can be discarded.

Glad you got that figured out, to me it's all confusing though. Trigonometry is where I surpassed my highschool teacher, but all this very abstract numberstuff is beyond me... I think my brain needs to be able to "paint a picture". How the data is stored in the file is not something one needs to understand to understand how the normal is calculated. Using the RGB values in the normal map to draw a diagram, the result is a hemisphere with a radius of 128, where the direction of the normal is the vector from 128,128,128 (the centre of the hemi) to any place on the surface of the hemi. The place on the surface is the RGB (xyz) value on the map. That's how it makes sense to me. I guess the two outer circles in your diagram visualise signed and unsigned? Still wondering why "they" decided to use the B value for normals aswell. Masami? Chosen? Anyone?

@drongle I think I get the idea of the signed and unsigned bytes, I just made the diagram from what I noticed though @ masami Interesting, but aren't you overlooking the fact that for every RB value there are two G values possible and for every GB value two R values? (128+G , 128-G and 128+R , 128 - R). Am I missing something? What you can do (and is used already) is using the fourth (alpha) channel for specular maps. No idea if this saves a lot of memory opposed to a seperate grayscale picture, as long as that's stored just like that internally. EDIT... I see I read it the wrong way, The B or Z value only covers half a circle, not a full one..you're absolutely right. I then wonder why the B is still used, maybe faster calculation? Might it be possible to flip normals using a normal map (something that's not very useful I'd say, but WOULD mean B covers a full circle aswell)? I also seam to remember something about RG being used for normals then B and A for specular. Any idea what the second channel for specular does?

Drongle McMahon wrote: I knew B (Z) was the normal to the actual geometric surface. Blue is only one of the three components, you really need Red and Green aswell to pinpoint the vector, which is the direction of the normal. What you determine with the three components is the end position of the normal. That's why you can't use all colours, the normal has a set length. Drongle McMahon wrote: I'm puzzled why tour diagrams treat the bytes as unsigned. Much easier to ubderstand if you treat them as signed so that waht was 128 is now 0 and means no component in that axis. The thing is without any normal mapping or smooth shading, the vector (normal) is perpendicular to the surface. One could argue rotating over more than 180 degrees is really rotating the other way, but I think it makes sense you can go both ways, so 128 is the middle then. Like the diagram shows, 128 is dead center of all possible vectors, you can't have a RGB colour that's not on the circle. If you start at 0 and point 45 degrees counterclockwise, you'd be in the negative which is not possible with RGB. I don't understand what you mean by signed or unsigned bytes. Drongle McMahon wrote: However, the thing I remain confused about is how the directions of X and Y (R and G) are set in the tangent plane. Without that, the diagrams could be spun around the normal without changing anything. What decides which direction is the X axis here? My guess would be that it's the U and V axes of the UV map. So I want to know if that's true. If that was your question I could have saved myself some time:) Yes the UV layout determines the UV or XY direction of all maps applied to it, normal maps being one of them. As far as a 3d program is concerned there is little difference between all the maps that can be applied. All need UV mapping. You can test it for yourself by rotating the UV layout 90 degrees and keeping the same normal map. Or keeping the same UV layout and compare the two different normal maps they'd have to produce the same result. EDIT maybe I now understand your confusion, forgive me if I'm wrong. R and G don't specify a place on the surface, it looks like that's what you are thinking..and my example doesn't help a lot then, since in this particular example they match 100%. R, G AND B are vector components (or like I said really the endpoint of the vector), the place on the map (pixel) determines the place on the UV map. If you make three of the hemispheres on the normal map, they will all look exactly the same, with R,G and B exactly the same for all three.

Indigo Mertel wrote: Do you mean I can't when I need to bake light and occlusion maps? Yes and no. If you want your moldings to have some occlusion effects, you can single out a piece of wall that covers the entire texture, then bake. If you have stacked UV islands, that won't work, because Blender will get information from all the overlapping islands and will try to stack the occlusion on the single texture. That will give horrible black spots. So make sure you have a texture with occlusion before you start stacking UVs. With light effects like baked in shadows from other objects, it will not work at all, unless various pieces receive the exact same shadows. Still you need to bake without any overlap.

Indigo Mertel wrote: Can I really overlap and let the islands stick out?!? I have seen tutorials stacking up islands but my understanding was that the islands had to be of the same size. And I didn't know that I could let the islands stick out. This would make things a lot easier. Yes not a problem, you can make one long wall in your UV thing, where only a fraction actually is on the texture. Like I said, you need to imagine the texture repeated infinitely in every direction. I wouldn't be surprised if Blender has the option to show that in UV mode, I know 3ds max has the option. Like Cale said, all you need to do is make sure all walls have the same height in UV mode, the height of the texture. So scale your islands uniformly (is that a word?) What you most certainly cannot do when you UV map your item this way, is baking (light/occlusion)) textures.

Indigo Mertel wrote: One solution I tought of is to crate one new image 1024 x 512 in size in the UV Editor fo each section of the walls, with some optimization for the shorter segments. Then,for each UV Map I would scale the shell grid so that i takes all the UV Map space. Is this correct? Do you have any suggestion? You can keep the original texture and its size without any problems. You do not need seperate textures or materials for your walls either, except for the ones you want to colour differently. Not working with Blender it's a bit difficult to explain, but I'll give it a go. What you can do is overlap your UV islands (different wall sections) if a wall is 4 meters high and 8 meters wide, let half of the UV for that wall stick out of the texture in UV mode. The texture in UV mode is repeated infinitely, so that way you will get a 2x1 repeat by default for that section (SL will show 1x1). If the wall is 2 meters wide, make sure the UV island only covers half the texture you see in UV mode, etc. You can overlap as many walls in the UV as you want, or place them next to eachother. Maybe some Blender user can explain it more detailed, including all the buttons to click .