exception

Hellow helpfull friends.

I have been trying to perform a certain test setup in preparation for an upcomming large project in which I wish to bake a Ls radiosity solution to a texture. I have run into a problem.
I have an object, made in Lightwave 8 with UV's. It was exported to Max 4.2 using Deep Exploration and subsequently saved as a .lp file. throughout this process it has been safeguarded that the model kept its uv coordinates. The model renders fine in Max, and the solution is perfectly calculated within Lightscape. The problem arises when using the M2T function. I use the 'project selected geometry into one surface' option. I set the first selection to none, the second to all. I set the mapping to UV. Then I deselect all options in the options panel, I just change the fill color so I can see the edges in the resulting map. Then I finish. LS calculates for a while and writes an image file which is only partially lighted. I have attached a screenshot of the model from LS, where you can seen that all surfaces were properly lighted (image one). I have attached the resulting texture as image two, and you can see that only about 1/10th of all the faces were properly lit in the texture, the rest are rendered black. The grey bits result from the fill color, and you can see the silhouettes of polygons which should have been lit.

I have tried this on two different machines, one with an educational licence (build 74) and one with a professional licence with build 104 (3.2 SP1). The results are identical.

When using the 'relight existing textures' it works fine (in a similar model which has a texture applied for testing), however in the project model there will be no existing textures. I have tried using a 100% black texture but this results in an erroneous lighting calculation. When adding the texture after the calculation all is black.

Does anyone know what could be the cause of this? It is a very properly modeled mesh and everything else, raytracing, etc, works just fine.

I also don't understand what the 'Use Object UV's' in the options section of Mesh to texture is about. When setting the projection to Object UV's, it should be enough, correct? This option only exist in the SP1 version.

Attached Images

	example1.jpg (30.9 KB, 80 views)
	example2.jpg (42.7 KB, 51 views)

seismograph

is it something like that?
http://www.cgarchitect.com/vb/5425-mesh-texture-uv-mapping.html

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richyrich

It is now possible to render your lightscape solution out to a standard uv map from within lightwave.............works very well.

check out www.evasion3d.com and look at the micorwave plug-in :-)

richard

exception

Seismograph:
No, I read that thrwad through and with him it renders _wrong_ in places whereas with me it renders _not at all_ in places. Also with me the Relight Textures option does work correctly. It is a fairly simple model, this is, why isnt this working?

also does anyone know what can be done to speed up LS's image saving? When calculating a map it takes perhaps one minute but then on 99% (when it is actually writing the file) it takes hours...

Richyrich: I don't see how microwave would help anymore than LW's own texture baker would? Importing a LS solution in modern day Lightwave is near to impossible when having a complex model. Thats why I want to use M2T. If I am missing something, please explain... Why would Microwave be a solution?

exception

If anyone has an idea to bake textures based on a LS model, please tell me. I have tried it in LS so often now that I am starting to believe the M2T function is just plainly broken. I cannot do it in Lightwave since the UV maps get lost when importing into LW 5.6, and 5.6 doesn't have a surface baker either. Higher than version 5.6 will void the radiosity information.
I have MAX 4.2, but I have no idea how it works. Is there a way to bake a texture in Max 4.2?

oluv

from my personal experience (and i really made many many tests) the mesh-to-texture function in lightscape is not mature and was unfortunately never brought to perfection anymore.
mesh-to-texture works well if you set your texture-coords by hand, but you cannot do this with a complex project. but with prepared uv-coords it doesn't render as it should. it can only render objects if there are no holes, that means if the object doesn't occlude itself with coplanar faces. i attached a simple example:
if the uv-coors were set right the left cube would render well. in the right cube you would have the outer faces mapped also into the inside small faces.

when i look at your example and at the mesh-to-texture output it shows exactly the same problem i had when i tried it.
you can clearly see that the model occludes itself, and only renders good at places where there are holes in the ceiling or in the walls, so that the light can come "through".

for my part i gave up creating lightingmaps with lightscape. it is a great program and i loved using it, but now it provide me the features that i need. i will probably have to jump over to max or viz as it offers exactly these features with a great uvw-unwrap.

Attached Images

meshtotexture.jpg (41.8 KB, 22 views)

oluv

mesh to texture must really have a bug in the final ls-version.
i played with "mesh to texture" and "relight existing texture" again and found that "normal" mesh-to-texture produces this occluding effect i was talking about, whereas according to your observation "relight existing texture" really works!

there could be a clumsy work-around for this, unfortunately i have no idea how to get your lightned map in color this way, i can only tell you how to get it in black/white, so imagine the following:
you create an unfolded uv-map for your whole model (with deep-uv or whatever) now let's assume your final-map will be 1024x1024, so create a white bitmap with this size and assign it to your lightscape solution as texture to all objects, choosing "object's UVs" for texture alignment. now choose relight texture and do mesh-to-texture, so your original bitmap should be "enlighted" with the lightscape shadows and lights. unfortunately you lose the original color of your objects if you assign a white map to them, you will only have the reflected diffuse light colored.

if you really want to tweak even more, you could color your source map (the white one) with the colors of the objects and make a "faked color map". it is very easy if you have a screenshot of the original-mapping-coords.
i made a little tutorial-grafic demonstrating the workflow, i hope you understand.
if i were you i wouldn't do the last step with coloring the map, that leads a bit too far i think, but a black/white map can also be useful, if you manage to mix the color of your original objects with the black/white texture afterwards... i could tell you how to do in vrml, but i don't know what you are going to do with your model...

i hope this helps a bit! and what a pity that lightscape doesn't have any support anymore. this little bug could be so easily fixed!

Attached Images

tutorial.jpg (72.5 KB, 34 views)

exception

That is very helpfull oluv!

In fact I came to the same conclusion, only I found a trick to use the material color. It is to set the 'blend' option in the material property and then, with a white map, it will do it exactly as the normal M2t should do, keeping the colors. I actually already knew this when I posted the message, so im terribly sorry I didnt say it before. the reason why im not using it is this: the test model above, which is in all fairness extremely simple, combined with a texture of 2500x2500 takes the mesh 2 texture utility about 12 hours to generate. Even with the command line utility. That on a p4 3.2 Ghz. I think that is not correct. I tried it on both systems, and on both this render time is absolutely intolerable. imaging creating 10 maps, which is not that much for a complex model. The normal mest to texture is unexplainably much faster, and I dont know why. I tried everything!

I am now looking into doing this with Quest 3D or alternatively rendering the solution with Gile. Both of them programs which I only encountered today and I find them completely unuseable for this purpose. So im running out of options.
Can you tell me if this lack of speed is common, does it happen with you too?
Should I take an older computer and install Windows NT 4 on it or something, would that help? I will attach the solution file here, and you can test it yourself, just make a 2500x2500 white image to load as the texture.

Attached Files

heavyshit2.zip (313.2 KB, 8 views)

oluv

may i ask how exactly you set your material and white texture to "blend" to get the color of the original objects? because i tried this too before, but as soon as i attach this monochrome material with texture to my colored objects, the original color of the objects disappears, even if it is set to blend. and that's logical, because the objects normally have all their own material with different colors, but then overtake the color of a unique white material, so you cannot even apply blend, because the new material is monochrome as well... do you get it?

but regarding rendering-speed. i know that mesh-to-texture is very slow when rendering with uv-coords. i made a test once with much more simple objects than yours and the texture-size was not that big, but it took ages to render. it is much quicker if you set your mapping coords manually. i don't know if this is a bug too, but i think this is the way how ls renders the model. as it has to render all faces simultanously to create a unique map, and i guess lightscape doesn't do this simultanously like other programs, but renders one face after the other and stitches the result at the end, so therefore also the break at 99% ...
i know this really sucks, but lightscape is really a bit out of date already, and at that time there was no real alternative and no other program could give you these features, "texture baking" was something "exotic"

giles is fine and simple and i played a bit around with it, but i think it won't manage complex scenes for radiosity.
as you mentioned quest: yes quest can do texture-baking and there is even a tutorial on their site how to do so. but i have no idea if quest can only bake own lights, or also an imported ls-solution. i also read in the quest-forum, that the users were not quite satisfied with the baking-feature, and referred to other programs for doing so.

this all sucks, but i have another tip for you:
do the following: download the 30-day demo-trial of 3dsmax7 from www.discreet.com
you can import your ls-solution and render-to-texture there. it is great and quick and you can try out all the new features, you can even do your uvw-unwrap there, which really works well or even trying calculate the radiosity solution directly in max i am quite satisfied with the radiosity results from max.
if you don't know how to get the original ls-vertex colors into the max viewport look into this thread because i had the same problem before http://www.cgarchitect.com/vb/7481-ls-into-3dsmax7.html

good luck!

exception

Thanks Oluv,

Well, what I did was calculate the entire solution and afterwards add a white map. Setting blend then results in the same reflective light properties as before the map was added and all the standard color settings of the material are saved to the texture.

I dont think this mesh to texture is going to work. I am now trying it through VRML. I managed to convert a LS VRML file to VRML2 using the convertor in Cosmo Player, and hopefully soon a friend will succeed in importing this solution into Lightwave entirely. I would then have the same options as max 7 would have in terms of surface to texture and so forth...