best way to prepare the rendering for PS?

[cmrhm]

What is the best way to generate the rendering for PS final touch?

Do I need to generate several passes? and How to do it?

 

I wish I could have a seperate shadow pass at least.

 

BTW, how to render black in background? I want to keep vraysky effects but don't want it show up in my rendering. The background in black would help me to edit the rendering easier.

 

Thanks.

[aaronrumple]

You can render elements and save out the element (passes) They will all be listed in your vray frame buffer when done rendering. Shadow is one of the elements. ZDepth is also very useful.

 

Save out as *.tif, *.tga or better yet *.exr and the file will have an alpha channel all set up for masking out the sky.

[cmrhm]

You can render elements and save out the element (passes) They will all be listed in your vray frame buffer when done rendering. Shadow is one of the elements. ZDepth is also very useful.

 

Save out as *.tif, *.tga or better yet *.exr and the file will have an alpha channel all set up for masking out the sky.

thank you, I am going to render out as .tga for testing.

 

there is no way to render an image with black BG?

[fadi3d]

there is no way to render an image with black BG?

 

.exr as mentioned above

[Stephen Thomas]

there is no way to render an image with black BG?

 

.exr as mentioned above

Yes, if you make your environment black then put your vray sky map in the environment override slot in your vray settings instead.

[aaronrumple]

Black background really doesn't help as if you are trying to select black to replace background you might get some dark shadows on the building as well. The alpha channel avoids that problem.

 

As noted, it can be done. But doesn't really speed the process.

 

Also I often mix the vray sky with a image for a more vignetting.

[Stephen Thomas]

Black background really doesn't help as if you are trying to select black to replace background you might get some dark shadows on the building as well. The alpha channel avoids that problem.

 

As noted, it can be done. But doesn't really speed the process.

 

Also I often mix the vray sky with a image for a more vignetting.

True. Definitely don't try and select your sky using the 'select colour range' option or magic wand. Save to Targa then go to Channels and Ctrl+click on the little thumbnail on the alpha channel to load it as a selection. You can then apply this as a layer mask to either your render or sky, depending on how you choose to set it up.

 

There are often a lot more subtleties to an alpha channel than just blocks of black and white, for example if you have trees or glass.

[cmrhm]

True. Definitely don't try and select your sky using the 'select colour range' option or magic wand. Save to Targa then go to Channels and Ctrl+click on the little thumbnail on the alpha channel to load it as a selection. You can then apply this as a layer mask to either your render or sky, depending on how you choose to set it up.

 

There are often a lot more subtleties to an alpha channel than just blocks of black and white, for example if you have trees or glass.

 

Thanks man. I now generate exr image then open it in PS. PS only allow me to save into .tiff file. Is it correct? It looks tiff image doesn't have alpha channel. For PS, do we use tga more than tiff?

 

because of this exr format, I don't have background issue anymore. it doesn't contain the background at all.

[braddewald]

Just use the vrayrenderid element for easy selecting of any object in your scene, including your bg.

[Stephen Thomas]

Just use the vrayrenderid element for easy selecting of any object in your scene, including your bg.

Quick and dirty yes, but certainly not the most accurate method.

[braddewald]

Care to elaborate?

[aaronrumple]

Care to elaborate?

 

For instance, if you have billboard elements, they will render as the planes they are on. Not as the nice cutout with opacity you're after.

[mattclinch]

I think I can elaborate on Stephen's comment.

 

By using a renderid/multi-colour mask to select areas of your model, you are relying on the accuracy and tolerance in either the 'select colour range' or 'magic wand' methods - neither of which are particularly accurate, and liable to spill slightly into neighbouring masks of similar colour. This can cause 'fringing' issues when pushing/pulling colour values or brightness of objects.

 

A more accurate method is to either render out pure luminance (black/white) masks and copy these into the channels, or pure un-overlapping RGB masks and ctrl-select the pure R, G, or B channel in PS and save it. These ways guarantee spot-on AA for each element in your scene.

[cmrhm]

Just use the vrayrenderid element for easy selecting of any object in your scene, including your bg.

 

I am experiencing Vray render elements currently. Since I need to be able to control my shadow in PS, which element I should choose? VrayRawShadow?

 

is there a tutorial link for the composing all these in PS?

Edited April 16, 2010 by cmrhm

[cmrhm]

the exr file I have after conversion from vrimg is always very bright, I need to use adjustments>exposure to bring back the darkness. Is this normal or I need to adjust my lighting?

[aaronrumple]

the exr file I have after conversion from vrimg is always very bright, I need to use adjustments>exposure to bring back the darkness. Is this normal or I need to adjust my lighting?

 

Look up LWF. You probably need to apply a .4545 (inverse 2.2 gamma) if you have not checked "Don't affect colors" and when you export the file from the vray buffer you do not have the sRGB button on.

[cmrhm]

Look up LWF. You probably need to apply a .4545 (inverse 2.2 gamma) if you have not checked "Don't affect colors" and when you export the file from the vray buffer you do not have the sRGB button on.

 

Where is sRGB button?

[aaronrumple]

Where is sRGB button?

 

..on the buffer window itself. (If you don't know where it is - it isn't on.)

[cmrhm]

..on the buffer window itself. (If you don't know where it is - it isn't on.)

Finally I got it. Thx.

 

Since I render to hard drive, so this srgb doesn't matter I think.