PROBLEM: Radiosity with separated meshes...

Radiosity with separated meshes doesn’t give the same result!

Hi, guys… I’ve been here for a while, but until now I have only seen your works. But this time I’m not just looking for info, because I’m actually doing a little job:

A friend of mine will show his final assignment of a building, he will have a stand to show a model (real model), but he asked me to do a virtual walk in the building. He actually has to create a 3D model in AUTOCAD®, so he will give me the final model ( in .STL ). Well, until now, everything is going fine, I have imported a preliminar model in Blender and works fine, but after doing some little Radiosity tests (malefico advised me to use radiosity to improve visual quality without having to worry about detailed illumination) I have a little trouble.

All the images were taken from a very small model, the actual one is very big (at least for me…) 80 m x 100 m !

This radiosity solution looks cool, I like it:

http://www.bellera.org/blenderfor/users/jedihe/Radio_Good.gif
Things to note about it: I subdivided the mesh twice before doing the radiosity, I also made a “remove doubles”(that was before subdividing… ; ) ).

Well, the result was quite good, but I can’t use the same steps with the final building: the texturing would be too hard! (of course, I will not use UV-map!..). So I asked him to generated independent parts, I imported them and tried to do the same radiosity solution (the presets used are exactly the same), but:

http://www.bellera.org/blenderfor/users/jedihe/Radio_Bad_Subdiv.gif
Things to note about the work: I used the same emitter planes as the first solution, the walls are separated from the floor, they are independent meshes. I also subdivided every mesh (except for the emitter).

http://www.bellera.org/blenderfor/users/jedihe/Radio_Bad_NoSubdiv.gif

Things to note about the work: I didn’t subdivide the meshes, the emitter planes are the same again.

Please, tell me how can I get a good result with independent meshes! I mean, a result like the first one!

hm, looks like you need to turn up the ‘hemires’

hm, looks like you need to turn up the ‘hemires’

I will try and tell you if it solved the problem.

jedihe

Having seperate meshes like that could be your problem, it’s measuring light inbetween the ‘cracks.’ Try overlapping them ot reconnect them.

I was testing on the model, and I found this: neither “separation” of meshes nor low “hemires” was the cause. I found that the reason is simple: when AUTOCAD® export on STL the whole model, it creates ONLY the needed geometry. When the separated parts where exported, there is some geometry “inside” (I don’t remember the exact word); I mean the floor doesn’t end in the edge where the wall starts, but continues. I think I haven’t explained it clearly, so if I have time I will post some snaps.

The SOLUTION: Make some geometry tweakings!, adjust the floor so it ends completely where the wall has it’s lower edge. That way I could use the separated meshes and avoid those ugly artifacts!

Thanks a lot!

jedihe

P.D. By the way, right now I am working on the final model and it looks great! I like the feeling of moving inside the structure, it’s real cool!

Well, what I meant was this:

http://www.bellera.org/blenderfor/users/jedihe/Mesh_Good.gif

that mesh works right for the radiosity solver, because the geometry is “THE ONLY NECESSARY”, but this one:

http://www.bellera.org/blenderfor/users/jedihe/Mesh_Bad.gif

Doesn’t work, because the floor passes below the wall, thus the solution gets ugly!

jedihe