Vray and speed

[cristoforo]

Everyone is always talking about Vray's speed....but I do not see it. Perhaps I am using the wrong settings? The scene here took 5.5 hours to render (it is a very simple scene) and it is only 1600x1300.....I usually render around 4200X.........and if I want to do an animation? I tried one tutorial, but with this same scene one frame took 30 min to render. That is too long for an animation! Are there secrets that I do not yet know about? And I am a little bit worried about all this color bleed on the walls, which are white. Is there any way to control this? I do not know what happened around the window......it is a bit splotchy. Any suggestions would be greatly appreciated! Thanks

[cristoforo]

HEre are the settings that I used.

[dlparisi]

Your Global subdivision multiplier is way too high. Try leaving it at 1 to start off with. At the same time raise your hemis. subdivisons to something like 25 and you min/max rates to -3/-1 and rerender.

[RErender]

Also,

For the color bleed you can lower the saturation amt. in the GI/Post Proccessing area and lower the gi send amt a bit for thr floor.

In the QMC rollout your settings are pretty tight a noise thresh of .004 is probably good enough and you might look at lowering the Min Samples a bit and the subdivs multiplier is way too much, I would recomend settings subdivs individualy and then just use the multiplier to fine tune the results.

If I am going for speed I normaly use the overlap Sample lookup instead of density based, also your normal threshold is a bit low .3 is probably good enough

For animations a major speed increase comes from using a stored GI solution.

[TRGraphics]

I agree with the others. I'm surprised you rendered that in only 5.5 hours with that global subdivision setting. The default (1) is usually good. Set Hemp.subs to 50 and saturation level to .6 and it will render in a fraction of the time with much smoother results. Also -4 -1 will help with the noise at that size of render.

Remember -3,-0 is for 640x480. When you double the size you can reduce this by 1 for each setting. -5,-3 is about the limit for interiors and thats for very large renders. Others may disagree.

Tony

[cristoforo]

OK....things are coming along better now....rendering is down to 1 hour. The view is slightly changed because it is part of an animation, but it is more or less the same view rendered at 1600x1300 then cropped later. Things are less yellow now, but that satuation setting effects the entire scene. What if liked the color of the entire scene except for the walls? Can I not just desaturate the walls? The original color is pure white there. The walls are better now, but still do not seem like "white" walls. Perhaps if I add the light above the ceiling fan I will see that the walls are white now. Something funny is happening on the back of the chairs and on the ceiling fan. Does this have something to do with the reflection depth? I changed the setting from 2 to 4, but saw no difference. In the 640x480 trial the chairs come out fine. Also, around the window frame there is a funny glow. In the window I am using a vray light with invisible and ignore light normals checked. Multiplier 4, type Plane, subdiv 12. Sorry if I am bombarding with questions, I just want to be sure that I have complete control of things before actually purchasing. I have two weeks to learn! I still have to face animations and exterior views!

[Da_elf]

i remember using 800subdiv in my light chache for this and it rendered in 10 minutes.



and thats with displacement in the scene

[flipside]

Can you post a 3ds export file of that scene? I would like to test it a bit.

The biggest speed increase for animation will be that you probably have to render it at lower resolution.

I disagree on the global subdivs multiplier comments. You can use high values, if your local subdivs are adapted to it (like you did, hsph was only at 8 for example). You probably did the appartment interior scene tutorial from vlado?

[cristoforo]

What did you do to avoid noise?

[Da_elf]

me? nothing that i can remember.

[TRGraphics]

cristoforo, can you post your scene so we can take a look at it?

Tony

[cristoforo]

Here's looking the opposite way....still 1600x1300. This took 1 hr 20 min to render. Though, I am getting these random black artifacts in which I do not know what to do to get rid of them. There were less of them in the 640x480 trial I first did. As for the animation, the resolution would be the standard PAL..720x486.....you are not saying that I have to go lower, I hope not.

How can I post the 3ds file here? Imageshack does not except the format.

[cristoforo]

I originally followed the "Rendering an interior scene" found in the tutorial section in the online documents. The comments I am receiving, though, are really helping me to learn. Thanks everyone. I think in little time I will be an expert....I hope! I am beginning to like this Vray.

[Da_elf]

what did you model this in? max? or is it imported from a piece of architectural software. i would check your objects for flipped normals, cooplanar faces etc

[cristoforo]

It is modeled in autocad.