Global sample quality

[DP]

it would be nice to have a global sample quality for glossy reflections and vray lights, this way its very easy to do a quick test and then ramp up the settings for a final render

cheers

rob

[flipside]

Yes indeed, now if you have glossies in several materials, and you want to do test renders to check some other stuff, you have to change every material so it's not glossy and renders faster that way.

IMO every parameter should have global and local controls, especially irradiance and AA settings.

[DP]

what also would be useful is a checkbox next to the global setting option so you can choose to use it or not

[flipside]

Like in finalrender

You have great content on your website btw!

[dbuchhofer]

I'd suggest looking at the SpreadSheet editor that Bobo made up.. (www.scriptspot.com/bobo/) and also looking at the set of filters that one of the Finalrender users set up for the editor.. as an example of what can be done in the realm of editing multiple things at once..

[vlado]

You can use the QMC sampler as global quality control, particularly the "Early termination" parameters.

for lower quality:
....increase the Amount
....increase Noise
....reduce Min samples

for higher quality:
....decrease the Amount
....decrease Noise
....increase Min samples

These controls have effect on everything: dof, GI, glossy stuff, area lights etc.

Color mapping mode also affects render times and sampling quality, since VRay tries to distribute samples based on the final image result.

The images below have the same subdivs for DOF (10), GI (50 subdivs, Direct), glossy reflection (50 subdivs, no interpolation), area light (10 subdivs) for all images. Notice how changes in the QMC sampler parameters affect the image quality and render time:











Best regards,
Vlado

[DP]

so is the min samples setting like a min global samples setting or is it just proportional?

i also wondered if there was a difference in brightness between the images? (its difficult to tell on my laptop here right now)

what does the "Early termination" do? is that like an early death of a %propotion of the rays?

[vlado]

There is no difference in the brightness of images, only in their apparent "noisiness".

The early termination algorithm allows VRay to shoot less rays than the full amount specified for a given value (gi, glossy reflection etc), if the result is "good enough" and adding more rays makes little difference in the final result.

The "Min samples" option controls how many samples (rays) will be taken before the early termination algorithm kicks in. More samples allow for a more accurate guess as to whether a value is "good" or not.

Best regards,
Vlado

[dbuchhofer]

Excellent.. always wondered what kind of trouble i could get myself into playing with the QMC

[DP]

thanks for the pointer vlado, i think we'll have to play a little with that QMC, however i do think it maybe more user friendly to have settings that are common to the material settings as globals, as this makes the approach more user friendly.

[marklazaro]

Thanks Vado . . this is an great tip. I'm going to use it for test renders. I make a lot of them.

The last image rendered 18 times faster that the frist one and it still gives you all the visual ques needed to make changes on alterations. On the other hand undersampling GI and Glossy reflections doesnt always do this.

regards,
mark

[losbellos]

This technik is excellent for outdoors scenes. Most of those (trees cubes teapots -tested) doensnt have much visible different with 1,0.01,40
but renders much much faster.