Rendering VRay Passes?

[bmcgonigle]

I'm hoping to get some direction on rendering in passes with VRay. I've got a fairly complex scene that is throwing error messages and crashing to desktop when initiating the raycast which I've come to understand as a memory issue (i'm on 32bit XP with 2gb of ram). I've done some googling and found that rendering the scene in passes is a solution until I can get more memory etc. but I don't have any understanding of how to utilize the passes feature in VRay. Any suggestions?

 

Thanks

B

[trino]

as far as i can tell, using passes will give you more control over the final image, i.e. color, values, bright, etc, etc

 

I think what you can do is to split your scene in background, midground and foreground geometry, and then composite them in post.

[rmccoy]

This thread has some of the elements posted that you need

 

http://www.cgarchitect.com/vb/35292-compose-rendered-elemnts-photoshop.html

[BrianKitts]

you're confusing two separate techniques. Since you mentioned that you searched this out due to crashing, I'm assuming that what you need is strip rendering, not rendering in passes.

 

When most people refer to passes with Vray it's about rendering different layers of information to composite in post. This would include things like a shadow pass, Zdepth, specular etc. These still require rendering a full image so it's not a memory saver, it's just a more advanced method allowing for more control in post production.

 

If this is a solution to crashing.....what you need to be searching out is strip rendering which isn't a vray specific method. If you have backburner setup already you're halfway there, it's just an advanced option in the network render output settings. If you don't have backburner setup, hit up the max help section and get it set it up even if its just running all locally on one machine.

 

Rendering in strips cuts your image into horizontal bands, so the final image doesn't require as much memory to render, then once complete you can stitch the strips together for your final image.

[Spooner04]

I second Brian, Strip rendering would be your easiest solution. If you are looking to render back ground, mid ground, and fore ground passes you should look into alpha contributions and mattes in the vray object properties. But I don't think that would help your memory issues.

 

Really you should just throw some more ram in your machine and get it up to 4Gb. Although not the cheapest, it would be the easiest.

 

If you've got alot of repetetive objects, I.E. Plants, cars etc. you could also use proxies to help reduce your memory usage.

Edited August 12, 2009 by Spooner04

[bmcgonigle]

Yes, the strip rendering seems to be what I'm looking for. With the deadline being tomorrow I've just gone the route of reducing the model where possible and scaling back the irradiance map parameters to try and get something done and out. Keeping my fingers crossedas I watch the prepass bar slowly climb.

 

I wish i could just throw more memory into the machine but I'm on 32bit xp so another 2gb would just go unused. I'm shooting to migrate to 64bit win7 shortly and at that point I'll invest in the additional 2gb.

 

Thanks for the help from everyone, I'll look further into the strip rendering and the passes technique for future projects.

 

B

[Spooner04]

Unfortunately going up to 4 gigs will allow you to use 3 gigs and not 4. But I would still recommend it. It will still leave more ram for max to run on. Maybe I'm really wrong here, but that was how I understood the ram issue.