Complete irradiance map?

[Austin]

I'm needing to generate a complete irradiance map for a scene we're working on. None of the camera shots have been decided on yet, so rendering out every Nth frame won't really work (like in an architectural walkthru). Normally for simpler scenes I'd just render out a series of camera angles, (with multiframe incremental) enough to where I've covered the scene. This is a rather large scene and using that method is going to be pretty time consuming... Is there any way that I can generate an irradiance map for the entire scene, with a preset amount of detail? If not, any ideas of a workaround?

I hope this was a clear explaination.

[vlado]

Render-to-texture may be able help you to generate an irradiance map for the entire scene - you just need to bake all objects and leave the irradiance map mode to "incremental add".

Best regards,
Vlado

[Austin]

Ahh, great idea. I'll give this a try tonight and post my results. Thanks for the quick response

[Giovanni]

Render-to-texture may be able help you to generate an irradiance map for the entire scene - you just need to bake all objects and leave the irradiance map mode to "incremental add".

Best regards,
Vlado

Ok, this is new for me, how would you do that, a bit more in details?
Using a still camera? And how would you make the irrmap not view dependant?

Thank you

regards

gio

[percydaman]

by baking it its no longer view dependant. so youd set your irrad map to add to current map, and bake an object. as long as you haven't cleared out the irrad map, choose the next object and bake again. keep doing that until youve done everything.

There'd be quite a bit of extra work though to do it. Your uv coords would have to be as efficient as possible which would require alot of manual work.

In the end, I imagine it would just be alot easier to do it the normal way.

[Austin]

Depends on the scene really. On a lot of objects the default unwrapper used with render to texture would work fine, especially if you knew that prior to mapping (which is the case in this incident--the scene is only roughly constructed and lacks uv mapping). If the object has to be unwrapped anyway, might as well. Also render to texture supports multiple objects at once, so in theory you can bake the entire scene in one go.

A hybrid system is sounding best so far... Baking the objects that you can easily and doing all others as normal. The only downside I'm seeing so far is a larger irradiance file.

Which reminds me, has anyone else had issues with their system only using 1 thread to load the irradiance map? Normally it's no big deal, but larger irradiance maps take a good deal longer to load on hyper-threaded systems (about twice as long )

[Austin]

I had a chance to do a series of tests and it looks like this method will work pretty well. I used 'incremental add to map' and just saved an ir map once the baking was done. The only downside is resolution... To get good results the RtT texture size might have to be large (1024-204 depending on the object. But if you can do the whole scene in 1 batch, just let it run overnight

[percydaman]

thats why i said uv coords mean alot. bad uv mapping, means you have to have a larger res render.

[Austin]

True, but it's still saving a ton of man hours.