VRAY 1.5 SP6 & 3DS design render problems!

[rstewart75]

I am still relatively new to using vray and as a architecture student i really would like to master vray but after reading and looking at countless hours of tutorials i am still at a lost. everytime i try to render, they either take too long and don't look good or just don't look good to begin with. the image always ends up being too bright or too dark and materials look washed out. could someone PLEASE help me so i can finally start to produce good renderings.

 

The attached image i couldn't even finish because i just kept increasing in time (i am on a time limit as I have a project due on tuesday and have invested my project in 3ds+vray and can't bail now)

 

the settings i used were :

adaptive subdivision (-1,2) clr thresh .01

reinhard (mult-1.0 burn .35 gamma1.8)

IM/LC (min-5,max-3 hsph subdiv 80 interp samples 20)/ (sub-1000 sample size .02 3 of passes 8

[Francisco Penaloza]

I think you forgot to attach the image, but to start, I will recommend, reset your V Ray since you are not to savvy with V Ray I would recommend you to start using the presents, default values are good enough for quick renders.

but first, set your Max gamma to 2.2 ( you can find more information than you can read about it online but for now just set it to 2.2 in all slot available)

then in VRay panel, activate VRay Buffer, set your color mapping to Linear, leave everything else as is, then in indirect illimination set IM to low, LC to 1000, sample size to 0.02 scale screen.

put your light source, if it is sun light, place a VRAy sun, when ask you to add sky to the environment say yes.

insert a VRay camera (this is very important) if it is a day shot, you can leave the values as they are, or change to Fstop 16, speed 80 ISO 100, if the image get to bright increase the speed if it is to dark lower the speed.

click render you should have something pretty decent now, your image may look a little dark you need to check the SRGB button in the VRAy buffer, that's all to get you started.

[rstewart75]

thanks, i will give that a try, but i have looked all over and how do you reset the vray settings?

[rstewart75]

[ATTACH=CONFIG]45974[/ATTACH]

 

The render looks a lot better now and went a lot faster...there still seems to be a bit of problems though...the render was dark but i turned on the srgb which did make it brighter, but everything still looks a little dull. i have vray recessed lights and they don't look like they are adding to the scene...its suppose to be an office environment...

[Francisco Penaloza]

What you can do is play more with the camera exposure, maybe try a Fstop6 or lower, speed 80 or so, ISO keep it at 100.

now if it is an interior I will place a big VRay rectangular light right outside of your windows, pointing to the interior and in the options of that light select portal sky.

Check the position of your interior lights, but I'm sure you will have to bump the intensity of those to compensate the Sun light coming from the windows.

There is not reset butons in the render panel, what I do is go to the render panel, assign render, select scaline, then go again and select V Ray that will clean up all your settings and give you a fresh start

[rstewart75]

[ATTACH=CONFIG]45975[/ATTACH][ATTACH=CONFIG]45976[/ATTACH]

 

Above are the two renderings- one without the gamma correction burned in and the other with gamma correction on. when the gamma is not burned in the colors look nicer and more realistic, but the overall picture is very dark --and when I apply the gamma correction (as I should be doing to be working in linear space) the image lightens up considerablely but the colors look dull and washed out and I lose the detail that i need for my interior visualizations.

 

i shall try changing the f-stop and messing with the intensity of the lights. I already had vray plane lights point towards the interior. the inside lights that I have in the scene are standard ies files (from what i read - it seems that these work better than the vray ies lights??) but i am still at a lost.

 

fco3d you said that the tweaks you suggested are starter settings, are the additional tweaks to the settings for producing a production render? (such as increasing the IM from low?)

 

thanks for your help!!!

[Francisco Penaloza]

The image that you said that it is washed out, it is actually OK and the dark one too lol it is the same image, one with the gamma applied so your monitor can read it better.

here is the thing, I always finish the images in photoshhop, all what you have to do is save your image as exr at 16 bit float point, be careful to save with gamma 1.0 so you keep your image in linear space, then when you open in photoshop you can adjust the final contras and glow and all your magic, and you'll see as you adjust the contrast and gamma in photoshop, you still have a wide range on lighting to play with.

I usually use VRay IES, they seems to render faster, not big difference with the regular ones, I may be wrong though.

For final images, all depend if it is interior or exterior and the final print size. but for what I see if you use the Medium or High preset with LC at 1200 or 1400 you'll be fine.

change your Antialising to DMC 2-6 noise threshold 0.004

it will take some time to render depending of your computer.

Here is a good read about Irradiance map

take a moment and this will help you alot

[Francisco Penaloza]

[ATTACH=CONFIG]45977[/ATTACH]

Herre is your image with a little love in photoshop, not to brag about it, just to show that do not try to only depend of the rendering software, most of the Pro Arch Viz is done almost at 60 render 40 post work, sometimes more sometimes less,

forgot the link

http://renderstuff.com/irradiance-map-vray-best-settings-cg-tutorial/

Edited December 3, 2011 by fco3d

[rstewart75]

thanks...i never save an image out as exr..(usually as a png or bmp) but I shall try that..I read about it, but didn't really understand it. so when you say i have more control over the lighting (for instance i like the glow you added to the strip lights) how do you exactly go about that? is there layers in an exr file? (i am not an expert in photoshop, but i am more than decent).

 

Also, you commented on the two images, that was before i got a chance to play with the f-stop and shutter speed as you suggested the second time around --so do you think I need to try your second suggestion for camera settings or do you think it would only over exposed the image?

 

I definitely thank you for your help--my apologies if it seems as if i am asking a lot of questions, just trying to fully understand things.

[Francisco Penaloza]

not problems at all, glade if my info can help you.

The advantages of work in float point is that you can fix or update your illumination in a better way instead of re rendering if your image was to dark or to bright, is very useful to tone down those burn out white in exteriors day shot.

The F Stop and camera speed set up depend of you and your scene, try to get as close as you can with your 3D camera and later in photoshop you can give the final touches.

The glow is a photoshop work, there is different ways to do it

For me when the image is 90% done, I save a copy in 8 Bits then copy the whole image, desaturated, fix the levels, tint the image with a warm color, apply blur and mix with the original image in screen mode, color doge or linear doge, depending.

I have wrote a tutorial about it, long time ago, all this in 8 bits only but is does apply for 16 or 32 bit float. The color mix may change but pretty much it is the same

 

http://www.fco3d.com/?p=292

[rstewart75]

Okay, Here are some of the renderings with your advice :-)....they are looking a TON better I think! And thanks for replying to the last comment, when I save them as exr's and start to tweak them you said that I could tone down the burnouts and I am wondering the proper flow, because I am not sure how to take the burnout off the renderings without ruining the pictures.....please help! (and I am definitely checking out your tutorial that you mentioned) Project is due tomorrow.

[Francisco Penaloza]

I can't see any images from your post.

What I do is I set the original image as background, then I apply an adjustment layer and fix the general exposure, if I have burn out whites, I apply other adjustment layer but I mask only the areas that I need to fix, usually I set up materials ID in 3D max for the main materials, then in photoshop it is easy to select what materials to fix, if not I paint by hand the mask.