render passes

[altbighead]

hi there ,

How can I get a render passes in mantra?

http://www.technolumiere.com/software/rend...RenderPass.html

I did serach on this forum but the video link is broken.Can anyone point me out right direction?

Thanks

[aracid]

hey altbighead

What u gotta look into is the deep raster page on the mantra renderer.

u can select what VEX variables u want to pass to the renderer. ie Cf - color

Of - opacity

above what they offer u,

u can pass any variable to the rendered as speparate pass,

be it custom or just shader variable. ie ur spec channel from ur shaders, or emittion variable.

When writing ur own shader, u can export arbitary variables, sometimes really usefull.

hope this helps

aracid

[DaJuice]

Hey altbighead, this was posted on the mailing list by Jesh Krishna Murthy.

I use deep rasters to do them for me and usually you can get away with doing multiple passes in one go. The key is that you tell your shader to export out the parameters and then you call the same parameter in the Deep Raster tab of your Output driver.

If you do not want to get dirty with the code just append a parameter VOP to whatever you want to render out as a separate pass. Make sure that the export button is toggled on. In the parameter name for that vop put in any name you find suitable to describe your values. Then go to the output driver and in the deep raster tab put in the same name in the VEX Variable window. Below that you will see a File/Plane name. If you want to append an image plane to your file then just put in a plane name ( can be anything you like but only works with sesi's pic format). Or if you want to render it out as a separate sequence of images (would recommend this) put in mypath/image_name.$F4.sgi or whatever. You can also select the colour depth individually for each plane. Very handy if you want certain things to be floating point etc.

This is a great way to do multiple passes at once. And if you are doing a lot of calculations in your shader the good thing is that for all the passes this only gets calculated once.

To get occlusion you can simple lay down an Occlusion VOP and export that (doesn't need any of it's inputs connected).

[deecue]

also, here's an old video tutorial on passes. for some reason it's not on the net anymore from what I can dig up.. but i had it lying around, so i'll throw it up on my server for the time being..

hth

Render Pass Tutorial

[michael]

thanks deecue...couldn't find this one here at home...

[altbighead]

thanks a lot for the video.

[MG]

It's a nice video indeed, I tried doing renderpasses myself and, without the video, I never realized I had to utilize render pre- and post-rendering scripts.

By the way, who made it again? (Wasn't it miguel?)

[itriix]

hello everyone. i was just curious if anyone still has the renderpasses.avi lying around and if they could please upload it one more time:)

thanks,

Jonathan

Edited November 9, 2009 by itriix

[deecue]

hello everyone. i was just curious if anyone still has the renderpasses.avi lying around and if they could please upload it one more time:)

thanks,

Jonathan

Hey Jonathan,

I just got your PM.. If you're talking about the video posted above, the link should still be active and working.. I never took it off of there and still seems to be good.. Also, just as a heads up, a *lot* has happened in H since that video was made.. Might not be best place to start..

hth,

dave

[itriix]

Thanks Dave,

I just noticed why the url wasn't working for me... The url in the post seems to have gotten butchered a bit *at least in my browser it is* Maybe during an odForce upgrade? who knows... Anyways, i figured it out, i just tried a few different url combos until i came up with this link!

Appreciate it,

*and yeah, i'll definitely take it with a grain of salt... i'm just scavenging for any bits and pieces of information on render passes*

Thanks for you're help,

Jonathan