CGTalk - a couple of questions about mental ray rendering

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erpel

11-07-2005, 05:07 PM

I have had a lot of trouble with mental ray not wanting to render my scenes sometimes usually just when they are starting to reach a good stage. In relation to this I have a few questions;
- I used to sometimes fix this type of issue by using the "render active" option and rendering the objects one by one to see which one was causing the problem. Up until maya 6.5 there was an option "render active" in the render globals but now in maya 7 I cant find it. Anybody knows what the equivalent is in maya 7?
- There is a particular error that appeart quite often " Error Mayatomr. "geometry" polysurface680 object is not a mesh Ignored What does it mean and how can I fix it?
- I sometimes wonder if there is a certain format for the textures that works better for mental ray ... what is better? targa? tiff? jpeg? or should I convert them into .map? is it worth it? I read about it on a thread but I didnt much get it. Specially: how do I go about it? please explain to me how to do it

I will be very gratefull for any advise

LehaS

11-16-2005, 11:54 AM

The geometry is not considered a mesh by MAYA if it doesnt have any faces.It means during the modeling proccess you somehow deleted all the faces of your particular object but it still exists in the DG of the scene as a node.In order to delete such object i usually "nail" it`s name in the output window and then paste it into outliner, get it selected and then just delete it and you are done

Maybe someone else can give you answers on your other questions....About .map format for your textures...... as far as i know it makes sense only if your textures are big as it will take lots of RAM loading them everytime MR has to use them....map format optimises them so MR can more easily read them....

Hope it helps...:)

djx

11-16-2005, 09:41 PM

Mentalray has problems with some kinds of tiff's. It doesnt like the ones rendered by maya, in particular. I dont think it likes the LZW compression. So I have found it safer to use other formats instead. I often use PNG and TGA (or JPG if the artifacts are not too obvious).

anthonymcgrath

11-17-2005, 08:32 AM

I render to .iffs myself as you can store z depth info - it'd be good to put up a sticky thread that discusses the pro's and cons of the different file formats in a neat order.

its a little off topic but its worth noting that mental ray likes .map formats for textures above a certain filesize or pixel size - its arranged so mr can split it up and use chunks of the texture rather than loading it into memory (theres a thread discussing this somewhere) but I dont know if its as fast with .iff textures (probably not because of the reason above) - I use them in maya as it displays the alpha channel in the view window...

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