help with radiosity

[marksee]

I am working on a crazy soffit design and have ran into a bit of an issue. Everytime the radiosity solution subdivides the mesh, the area around the hole for the recessed lighting gets a very bad shading solution. It doesnt seem to matter the method of creation, boolean, shapemerge extruded poly, editable poly or mesh - and was hoping for a bit of input. I had even created a hexagon around the round opening hoping to subdivide the long triangular faces, but nothing seems to help. Any suggestions? Thanks!

[neko]

can you post your radiosity settings ? that might help solve the problem.....

[Fran]

Hi Mark,

 

How is that mesh being smoothed? Did you model it in VIZ or something else?

[marksee]

I modeled it in viz. outlined it with a spline, extruded to 0" and turned it to an editable poly. from there, I shapemerged the outlines of the can openings and extruded them up. I then turned it back into an editable poly and applied a smooth modifier onto it to clear the smoothing groups. I upped the iterations with the radiosity parameters and it turned out quite a bit better, I have just never ran into this problem before and don't know if there is a "cleaner" way to do it. From there, i decided to make a plane with 10x10 subdivisions (to help with the long triangular faces) and shapemerged both the soffit outline as well as the recesses for the cans. this is a bit cleaner, however, it doesn't seem to be perfect.

[marksee]

Ok, so after solving the previous problem, a new issue has presented itself. Does anyone have any links to tutorials relating to displacement maps for materials. When using radiosity (or mental ray it seems) my bump map for a tile pattern flattens out and creates gray colors in areas where the bump should be. Previous forum articles suggest that the displacement map should be used as opposed to bump, however, applying a tile map to the displacement map makes the floor "crumple" and displace way too much - even at 1 (in the displacement value). I am obviously doing something wrong. Does anyone have any suggestions or tutorials for viz? I haven't ran into this problem before simply because I haven't paid attention to the issue and I am shooting for a bit more realism for future renderings.

thanks - as always.

[Fran]

Hi Mark,

 

If you are using an Architectural material, you can reduce the Indirect Bump scale in the Advanced Override parameters. That might help, especially with a floor.

[marksee]

But how do I get the bump map to act normally - as in the way it does with the scanline renderer w/ standard lighting? It seems that everything has gone flat....

[berten]

Radiosity is not the best way for your rendering, it's better for gaming or realtime. Your ceiling has not enough subdivisions to give a proper result.

But i see that's it for a tube light or something like that. anyway the reflective materials will never render properly.

So use the global subdivision settings and create a max mesh size of 20 and a min mesh size of 5. Initial quality must practicaly reach 100 but this is impossible but try as close is it can get. and use automatic exposure control, and tweak a litle bit. I'm sure you will get a result at that point that pleases you much more than what you reach now. good luck , but you'll learn a lot of it. i putted a radiosity render i made two years a go with it check this out.

[marksee]

thats pretty good. I just have a hard time using standard lights and making a scene look realistic. I've been working w/ mental ray, however, it seems that the renderings are taking quite a bit longer - and don't have access to vray at the moment. The purpose of radiosity is to keep the rendering times down so that I can create a file for both stills and an animation. Which engine is the best for quality and speed (the ever-going battle) for animations? I have quite a bit more work done - all except furniture and filler - and the scanline w radiosity is only 30 some seconds.... mental ray had me around 1:46. I solved the soffit issue with manually changing the soffit shapes subdivisions with advanced lighting while keeping the global setting relatively low. Thanks for all the advice.

[berten]

For fast renderings with good results you can use the standard render engine, just use 6 directional lights without shadows point them at every side (front back sides bottom and top. then you rule them so they have all a different value below 1 so then every wall will be visible and not overlighted, you can then just use a spotlight with shadows to show daylight or any other, that's the fastest way with good result.

[marksee]

But with mental ray - for quality stills - you use displacement as opposed to bump correct?