Store with irrad. map question

[neba77]

Ok, here is the question....

 

What are your experiences regarding interior lighting, and using store with irrad. map unchecked with vray lights?

My dilemma is this: is it possible to get the similar quality in gi with this option checked considering lower render times.

 

My experiences tell me that when left unchecked the quality of gi is perfect, but at cost of rendering time which is inflenced by high light subd. lowered noise thresh. & other stuff used to eliminate noise.

 

On the other hand checking this option requires cranked up irrad. map parameters so in the end i get similar render times considering that the calculation of the map alone takes a few hours. Irrad. map settings: min\max rate -4 ,-2 , hsp subd 50, min samples in qmc sampler 100, glob. subd. mult. 2

And preset set to very high, then had min max rate changed. Plus the artefacts that i almost alwats get in poorly lit areas, that i dont have when leaving the option unchecked.

 

What are your experiences, & am i doing something wrong...

[Tyorl]

Hi, if it possible please attach images with artifacts. In fact Checking "Store with Ir.map" in light causes a blured shadows so as your light computing with irmap, to get more good-looking shadows u have to raise your min/max. I always check this options for lights, so I have faster computing with normal quality. If this option unchecked and u have a lot of objects in the scene, as u said, u have to raise your Light subdivs greatly, and your computing time increasing great.

So a lot of artifacts may appear by using different computing methods for IR.map for example the default is "Delonge" but I prefer "Overlapping" it is more blurry but less artifacts.

 

This is my point of view.

[neba77]

 

Ok i have marked the artefacts i was talking about... It is rendered with store option checked. I keep getting the invalid lightmap samples warning and am gessing it has something to do with the problem. When store with irrad. map is left unchecked the artefacts are gone, but render time doubles...

 

Thnx in advance!!

[Tyorl]

First about Ir.map: I think u r still using "Delonge"? Try to switch to "overlaping" it is more faster and this may solve your bugs.

Second about LC: so r u computing it with screen mode or fly-thru? What sample size do u use? What system mesuare in your MAX(note not the ones where "Generic units" are, but those "System Units"), for example if your System units are mm the size-0.05 and 1000-2000 subdivs in screen mode.

 

So the main reason of Invalid LC samples are small subdivs.

 

Hope this helps.

[Christopher Nichols]

Just something to keep in mind. When you select "store with irradiance map" in your Vray light, your Vray light is only working in diffuse, since the irradiance map store indirect diffuse light. You look all specular/reflection of your light.

[neba77]

Ok, to keep the long story short, here are the settings:

 

 

I cant seem to get the hold on the irradiance map shadow detail. Is it really necessery tu use such high rates as -3, 1 on resolutions like 1280x1024 to keep light leaks at bay... light leaks like this:

 

 

 

I have been avoiding using irrad. map for first bounce (checking store option ) for the reasons i posted in the image above, but rendertimes are becoming an issue, for the client i am working for is asking for more and more detail in light and geometry, and i am getting rendertimes of 5 to 7 hours for a 1280x1024 res. on an standard desktop machine.

 

Thank for the replies guys, you are helping me a great deal!!!

[Christopher Nichols]

well you may need to go to at least -3,-1. -4,-3 is not going to cut it. you can also turn down your subdiv to 50 or so when you do that.

[neba77]

So basicly, there are two methods for precise gi?? One is unchecking store.w.irr. map, and the other checking the option and using high min max rates...

Christopher, thanks for your time, ther is only one more question... in qmc sampler, minimum samples tab, i thought, that by telling vray to rise minimum samples value he would have more detailed irrad. map even in lower min/max rates. thanx

[Christopher Nichols]

So basicly, there are two methods for precise gi?? One is unchecking store.w.irr. map, and the other checking the option and using high min max rates...

Christopher, thanks for your time, ther is only one more question... in qmc sampler, minimum samples tab, i thought, that by telling vray to rise minimum samples value he would have more detailed irrad. map even in lower min/max rates. thanx

 

Well, if you check store with GI pass, that mean that your DIRECT light is calculated as a GI pass, if you uncheck it, that mean that your direct light is calculated as a direct light and your GI pass only indirect light. The QMC tab effects more then just GI. It effects all sampling including AA, soft shadows, etc... if you really want less "noise." you can lower the noise threashhold in the QMC tab. That is generally the best way to go. Be careful as it is very sensative. Try and lower it to 0.002, and take your minimum sample back to 8. If you still want less noisy samples, lower the Adaptive Amount from 0.85 to 0.5 or so.

[neba77]

well, that is it than.... thanx again for all answers... more questions soon

[neba77]

Well, that is it then... thanx for all the help, more questions soon...

 

p.s. sorry for double posting my mistake!!