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JulianW
07-29-2005, 09:51 AM
Hi folks,

I want to be able to 'bake' radiosity based on a lower resolution render of a scene and apply it to the full res version.

The problem is that I want to be able to do this with textured surfaces (ie with a color texture) so that the radiosity part of the surface is baked out but not the low-res texture so that I can then apply the texture in the high-res version.

I can't seem to find a way to do this and get a similar looking result in the hi-res version. I've tried using Surface Baker and PSD export to achieve this but can't seem to get the 'baked' data to apply with the color texture correctly,

anyone got any clues as to what I'm doing wrong??

cheers,


JW.

Dodgy
07-29-2005, 11:02 AM
Are you baking illumination, then applying that setting the diffuse to 0 and luminosity to 100 and multiplying the lum map on top of the colour map?

JulianW
07-29-2005, 12:39 PM
Sounds pretty much exactly what I've been doing. I can't seem to get surface baker to create a version without the color baked in, so I'm using PSD export, and the result seem to come out brighter in my tests.

I've tried ramping down the luminosity but there doesn't seem to be a constant factor involved, and the results never match a pure render that well.


JW.

toby
07-30-2005, 09:37 PM
Are you sure you've got nothing but 'bake illumination' checked? Or do you think that the color might be from the radiosity bounce color bleed? If so, keep it!

JulianW
07-31-2005, 05:39 PM
Hi nothing but bake entire object and bake illumination is checked.

Here's the result (and I'll attach the lwo, and lws files in a zip)

Plain Radiosity Render:
http://vbulletin.newtek.com/attachment.php?attachmentid=22133&stc=1

Output from baking:
http://vbulletin.newtek.com/attachment.php?attachmentid=22134&stc=1

Render with baked map applied as described:
http://vbulletin.newtek.com/attachment.php?attachmentid=22135&stc=1

Any ideas where the difference is creeping in???

cheers,


JW.

toby
07-31-2005, 07:49 PM
You've got a red ball bouncing light onto the grey surface, so your illumination is red - that's the way it should be, not sure why you'd want it any other way :confused:

toby
07-31-2005, 08:16 PM
I tried putting the bake image in the luminosity channel, is this what you're looking for?

JulianW
08-01-2005, 05:13 AM
Hi,

I wanted to keep the red colour bleed off of the ball, its in the scene to check that I'm getting properly coloured illumination.

My problem is that if you look at the first and third images I posted, I'd like them to come out the same. As it is there is a noticable difference between them, so if I wanted to switch from a pure radiosity render to a baked one then there would be a noticable jump in lighting levels.

sorry if that didn't come across too clearly,


JW.

toby
08-02-2005, 12:38 AM
If your surface is lighter than the original render, that means that something is illuminating it besides the map. Make sure you've turned off any diffuse and anything else that will increase the luminosity over the map.

JulianW
08-02-2005, 06:43 PM
Hi,

everything's off except the luminosity at 100%, no shaders, no image filters, nothing of any kind I can think of to change the render.

It all works fine if I don't try to multiply the colour map over the top, but as soon as I do that the whole render gets paler for no obvious reason.


JW.

toby
08-02-2005, 08:59 PM
Try setting the luminosity to 0 and putting the map there instead of the color channel. If you have your illumination in the color map in addition to 100% luminosity, it'll be too bright. Sorry I'm having a hard time explaining it clearly - I don't do the multiply thing so maybe I'll just do some settings and show that to you

Krom
08-03-2005, 02:40 AM
May be try disabling ambient lightning when baking illumination ?

JulianW
08-09-2005, 11:56 AM
Hi,

apparently you need to set the gamma to 0.52 on the image when you load it, don't ask me why, it seems to be due to the way the blend modes work on textures.

It gets mentioned on this page http://www.altyna.com/lw/specrefl.htm (thanks to cyphyr over on cgtalk for pointing me to that one)

Thanks for all the ideas,


JW.