Image Based Rendering in Maya native render?

[sharktacos]

hellooooooooo ???

anybody home?



Bueler?

[shehbahn]

guess this goes to show how many people use the Maya renderer ? (j/k)

afaik you couldn't trace rays from the API in Maya 5.0 and the feature has only been implemented in 6.0 - so you'll probably have to wait a little bit until you start seeing ambient occlusion / dome light type plugins for Maya, and i doubt they'll be very fast.

as for IBL, assuming that Maya can read a floating point format as a texture, you can get some basic things done with just an environment map and blur functions.

[sharktacos]

actually there has been an ambient occlusion plugin since 4.5
Its called "RayDiffuse"

[Andrew W]

as for IBL, assuming that Maya can read a floating point format as a texture, you can get some basic things done with just an environment map and blur functions. I don't think it does. There was muttering about supporting 32-bit .bmp images in Maya 6.0 but I have no idea if that's actually working or not.

Could you not use Mental Ray since that ships with Maya these days? You can do all the fancy new tricks in that.

Failing that have a look at HDRShop on Paul Debevec's (http://www.debevec.org) website which has a free plug-in that will sift through an HDR image in HDRShop and output a set number of directional lights into Maya with appropriate intensity anc colour values. You'll probably want to write a MEL script to cycle over all the lights to attenuate the values in Maya afterwards but that's pretty easy and Bob in this case, might be your uncle...

Best,

A

[sharktacos]

Yes I could do it in Mental Ray theoretically. But mental ray is not always an option since the renderer is not free (unlike the Maya renderer), and since it is not possible to just "switch it on" like one would raytracing since it involves redoing all the textures and lighting on a shot, I would like to have other alternatives as well.

I saw that there is a tutorial on pixho.com for IBL in Maya. This is rather old however. So I was curious what other people's approaches have been and whether they have used this methodology or another one.

Andrew I have a question for you about the "ant" commercials you all have been doing. Are you using AO and IBL on this? Or is there also some sort of radiosity or raytracing or whatnot you are using in addition to get self-bouncing light on the ants?

[shehbahn]

trolling through the Maya API message board - it seems tracing was impemented in the API at least since v. 5.0, so my bad. might be that now that almost everyone is using the free MR licence, few people bother to write this kind of plugins.

[Andrew W]

Andrew I have a question for you about the "ant" commercials you all have been doing. Are you using AO and IBL on this? Or is there also some sort of radiosity or raytracing or whatnot you are using in addition to get self-bouncing light on the ants?


I'm afraid I don't know. I work in the feature effects department not commercials and we're actually in different buildings so we don't have that much direct contact. I'm guessing that it would be a hybrid approach mixing regular CG lighting with some ambient occlusion and IBL. As for renderer could be Mental Ray or the Maya renderer, I know they use both for commercials. I doubt any radiosity type calculations would have been done. The turnaround times on commercials wouldn't allow for it.

Best,

A

[sharktacos]

thanks Andrew.

It seems to me that while ambient occlusion is generally useful, IBL is really only useful when working with live action. In a pure CGI scene where there is not an encompassing world to base the IBL image on I would think that traditional lighting might be a better bet. Thoughts?

Also while IBL simulates the objects in an environment bouncing light onto an object, it does not account for the geometry itself bouncing light on itself. This of course works with radiosity, but that is too slow for production. So are there any cheats to replicate this self-bouncing light from geometry (other than traditional "bounce lights" of course)?

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