Please explain for me....

V-Ray V-Ray for 3ds Max General
1

…:slight_smile:

Here’s what i do (and maybe i shouldn’t…maybe that is the answer :slight_smile: )

I seperate my large still renderings into two process.

1) The prepass. (don’t render final image) I unload all my rpcs (in xrefs) and turn off my displacement (usually this is just used in carpet or masonry…something ‘short’). Then i render out the irraidinance map and it’s automatically saved.

2) I reload the xrefs, turn on the displacement and set the irraidiance map to “from file”.

3) Then i close and re-open the file (so everything is nice and clean…seems to clear up some problem buckets). Then i render the scene.

What i don’t understant is why in step #3 it takes so long to go through the prepass again. Isn’t this the data that was stored in step #1? It seems like it is being recalculated when it should just have to load from a file.

Where has my thinking gone wrong?

thanks in advance.
…gregory
http://mertens3d.com

2

If it’s doing another prepass, you have ‘use interpolation’ checked on in one or more of your materials, either in reflection or refraction.

Use the vray material control script to turn it all off in one go.
http://www.scriptspot.com/3ds-max/vmc-vray-material-control

3

I think its taking long because of the displacement.
If you did not exclude it from getting GI in the options it will be hard to calculate even with saved IR maps.

4

I do have ‘use interp’ turned on in all of my materials with a non 1.00 glossiness. I thought this was suppose to be faster and simple tests proved that out (a year ago or so).

Is it a general mistake to use interp., or is this a bug, or just a thing?

thanks for the info and the link to the script

…gregory
http://mertens3d.com

5

So what is the generally accepted work flow (with regard to short displacements like this)? It seems like i wouldn’t want to exclude the carpet…right?

…gregory

(i’m tired)

http://mertens3d.com

6

Thats how it works though - those prepasses are to work out your glossy materials.

Incidently, I always leave displacement on for irradiance maps - can mess up sometimes if you have large values.

7

the use interpolation method works faster if your rendering everything in 1 step. on a saved irradiance map methos its longer

8

good info!

k…while i adjust for this. Can you, or someone else confirm this.

If glossiness is set to 1.0, then “use interpolation” has no effect (affect?) whether it’s checked or not. Correct?

…gregory
http://mertens3d.com

9

cool beans!

quick test. From the same irradiance file.
with interp off: 6:24
with interp on: 12:18

don’t ya love learning new things that save time or make a better image?

…gregory
http://mertens3d.com

10

use this script for switching all interpolated reflections from on to off with a single click:

http://www.scriptspot.com/3ds-max/vmc-vray-material-control

11

hey guys

wow this script just saved my life, i love it!