Another Combustion question

[timmatron]

I rendered out some frames with a background sky map and saved out as tiffs with alpha channels. When I bring them into Combustion, it automatically removes the background/alpha channel. That is actually really cool that it does that, but is there a way to NOT make it do that, and be able to keep my background map?.....eric.

[dapeter]

In Combustion 3 at least, under the footage controls and the 'Source' menu, you can change the loader to 'Color' or 'Alpha' or 'Color+Alpha'... you can also invert the alpha from here.

[timmatron]

I thought that would work too, but it's not working. I've tried all I can think of to get the background to show up, to no avail. Thanks though.

[RErender]

Hmm, not sure what it might be.

Do the tiffs have an alpha in photoshop? I usually use pngs or tgas and they always work.

If you are in a hury you could do a matte pass, just render the passes without the background and with the lights and gi turned of, should render pretty quickly (I recomend using tga or png). Then bring that footage into the comp, put it at the bottom and turn it off. second add a "compound alpha arithmetic" channel operator. In the operator choose the matte footage , alpha and set. Should get you what you need.

[timmatron]

Whats really weird is that while Combustion automatically kills the alpha with tiffs, it will not mask off the alpha with a png or tga. User error....

[timmatron]

Yep, user error. I saved the tiff to a tga again and this time i can turn the alpha off & on. Wonder why tiffs w/ alphas don't work correctly in Combustion. I like using them beacause the Win XP picture viewer can open those, but not tga's. It's a lot faster viewing them that way than photoshop. Maybe I need Acdsee or something like that.

[Joost Ink]

infranview rocks that way and its free

[timmatron]

infranview rocks that way and its free

Thanks, I'll have to try that.

[studioDIM]

Combustion's image loaders are flaky, and do have confirmed troubles with EXRs, RPFs and Tiffs
Generally the updates fix one and break the other...

Welcome aboard

Lele

[RErender]

Reminds me of the time at Siggraph, Greg Ward was giving a short talk on HDRI's, when in the question session that followed the Tiff guys...

[rpc212]

Reminds me of the time at Siggraph, Greg Ward was giving a short talk on HDRI's, when in the question session that followed the Tiff guys... Laughing

The tiff guys what?

[panthon]

I haven´t got a problem importing rpf´s into combustion, nor tga´s neither tiffs... Exr imports diferently, but i guess that´s the reason why it can look different in photoshop than in max...you must adjust it in order to see it properly, via luts or via gamma controls...
About the strange issue of background disappearing, just make sure combustion hasn´t checked the invert alpha tick automatically. It does it randomly and it´s very annoying...