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Larking about
About Truespace Archives
These pages are a copy of the official truespace forums prior to their removal somewhere around 2011.
They are retained here for archive purposes only.
Larking about // Work in Progress
Post by kena // May 22, 2007, 7:00pm
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kena
Total Posts: 2321
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Not sure really where this will go if anywhere. Just playing about trying to understand V-ray.
Any sugestions on what I might try? |
Post by kena // May 22, 2007, 7:13pm
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kena
Total Posts: 2321
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To make it easier to give sugestions, here are the Material settings for all my objects so far. |
Post by kena // May 22, 2007, 7:14pm
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kena
Total Posts: 2321
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and finally the "floor" |
Post by Jack Edwards // May 22, 2007, 11:58pm
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Jack Edwards
Total Posts: 4062
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I've found that a good place to start with VRay is one shadow casting spot light and GI. Lighting is everything for VRay. ;)
Once you have a good light setup, drop a few objects and try a few materials out.
For faster renders while you're still learning, change the min rate to -6 and the max rate to -2. It'll be a little less accurate but it gets done a LOT faster.
If you're doing refraction, make sure to raise the QMC Depth to the number of bounces you need for the light to pass through each of the surfaces. It's defaulted at 3 which isn't enough for hollowed out objects.
Use Irradiance for Primary GI and Direct secondary for faster renders and Lightmap secondary for smoother/cleaner interior and caustics renders.
Hope that helps!
-Jack. |
Post by Grommit // May 23, 2007, 12:13am
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Grommit
Total Posts: 32
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Thanks for posting this Jack. This kind of practical information is really useful. :) |
Post by Jack Edwards // May 23, 2007, 12:23am
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Jack Edwards
Total Posts: 4062
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You're definitely welcome. If you guys need help with something specific, let me know and I'll see what I can do. I'm going to be off-line most of today, but I should have a bit of time tomorrow though.
-Jack. |
Post by Birdnest // May 23, 2007, 9:14am
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Birdnest
Total Posts: 152
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Yeah, I know how you can help me....
How can I purchase Vray and TS7.5 with little money? :p j/k.
Keep this thread going! I want to learn as much as I can with Vray, though I don't have it but ah well lol. |
Post by Jack Edwards // May 23, 2007, 12:13pm
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Jack Edwards
Total Posts: 4062
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LOL Birdnest that one's easy! Get invited to beta test. ;) :D
If I get a chance I'll post some starter examples this weekend, or early next week. Just make sure to bump the thread and bug me about it. :p
-Jack |
Post by kena // May 23, 2007, 8:46pm
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kena
Total Posts: 2321
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NOTE This program is not good for my health. I should have been in bed almost an hour ago... been playing with this for hours
so...
The Picture
6337
and the settings...
6338setting QMC depth or 1st bounce any higher washes out the clear object and the cube for some reason. only way I could get the split sphere to show well enough was to use a light image. |
Post by parva // May 23, 2007, 10:53pm
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parva
Total Posts: 822
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description of the vray panel (for those who understand german) :
link (http://forum.3dspace.de/thread.php?threadid=125&sid=32334263895e783a7fc72dbb610cbc70) |
Post by kena // May 24, 2007, 1:35pm
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kena
Total Posts: 2321
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I will work more on this perhaps tonight... Uru Live is having a bit of a story happening, and a new age, so will be there first thing... I may even skip dinner! :D |
Post by kena // May 24, 2007, 6:56pm
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kena
Total Posts: 2321
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It's so hard to decide what to do in a day when new content comes to your favorite online game. Anyway, there was a space when the Authentication servers were so overloaded I could not get back in, and I did this.
Anyone know how to change that format? the drop-down doesn't say. |
Post by Jack Edwards // May 24, 2007, 7:51pm
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Jack Edwards
Total Posts: 4062
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Hi Kena,
First thing I notice is you're min and max values are backwards. The min value determines the starting size of the buckets, the max value is the final size of the buckets.
Basically the way it works is a value of 0 means that it will evaluate for each pixel. Positive numbers mean that it renders more than one sample per pixel. Negative values mean that it sample over more than one pixel and then based on the interpsamples value interpolates between them.
VRay in TS is set up to use adaptive sampling so if you start with a larger (negative) number for you first pass then it can figure out where it needs to do more sample and where it needs to do less for each itteration. The number of itterations is the difference between the min and max values.
Try:
MinRate = -6
MaxRate = -2
This will give you 5 itterations.
I also increase the Distance Threshold to .2 so I get more advantage from the adaptive sampling. Edit2: LOL missed that you'd already raised this value. ;)
Shader values can play a large effect on your image as well, so you may want to start with basic matte shaders and until you get a feel for the lighting. GI is very sensitive to stongly saturated colors, so you may want to try more realistic mutted tones.
You're latest render is already a large improvement over the first one, so keep it up! :)
Edit: oh yeah and you're HemiSamples value is too low, if it doesn't slow your renders down too much, you may want to try raising that to say 50. And I'd practice without the HDRI image since that adds a lot of different colors into your scene. A basic blue-gray or gray should be fine.
And don't forget to raise the QMC Depth value if you need to bounce the light off more than 3 surfaces. Especially if you're doing caustics or multiple reflections. I think 6-8 is more necessary for scenes with caustics or lot of reflective items.
-Jack. |
Post by kena // May 24, 2007, 9:29pm
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kena
Total Posts: 2321
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aaaah.... so my colors were too bright!! that explains why they got washed out if I didn't use an environment map.
so more like this?
6370
6371 Birdnest, if you get on the Beta team, you are going to just LOVE this! Lots of fun to learn.
:jumpy: |
Post by Jack Edwards // May 24, 2007, 10:46pm
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Jack Edwards
Total Posts: 4062
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How many lights do you have in the scene?
Edit:
Oh yeah and and you'll want to set your first and second bounces back to 1.0. ;)
And that blue + reflection on the ground plane is killing me... :p
-Jack. |
Post by kena // May 25, 2007, 4:57am
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kena
Total Posts: 2321
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only the default lights that were there when I started the scene. I think it had 3 infinite and 2 spotlights. the spotlights have shadows added... good think though... maybe if I got rid of some of the infinite lights. |
Post by kena // May 25, 2007, 5:13am
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kena
Total Posts: 2321
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getting faster at this...
with only one infinite light.
6374
With only two infinite lights.
6375
aaaaand settings
6376One infinite light looks too dark to me. And I reduced the floor reflection for you Jack. |
Post by Jack Edwards // May 25, 2007, 11:38am
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Jack Edwards
Total Posts: 4062
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The two infinite lights is too much. Usually an infinite light would represent parallel rays from and intense distant source like the sun.
I would delete all the lights and get the GI about where you want it but slightly dark, then add one spot light as your key light. If you need to you can up the 1st bounce to get more light.
About your materials, make sure ambient is set to zero. Reflection + Diffuse should equal 1. So if you up reflection, you should reduce diffuse to match.
For example 0.2 reflection + 0.8 diffuse = 1.0
:)
Oh yeah, and don't forget adaptive AA. :D
-Jack. |
Post by kena // May 25, 2007, 6:45pm
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kena
Total Posts: 2321
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OK - removed all the lights and spent 2 hours trying to get the GI so I could see the scene - then I added just one spotlight. forgot about first bounce, but I have 1st set to 1 and 2nd set to 3. went through all my materials and evened out the Reflection and Defuse to equal 1.
NOTE: I found that putting reflection higher than defuse made it look kinda wonky. Turned on the Adaptive Anti-Alias and here is the result. |
Post by Jack Edwards // May 25, 2007, 7:37pm
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Jack Edwards
Total Posts: 4062
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Looking much better.
Couple of questions, why only one pass at -3?
That's a bit high for a single pass and you'll probably get inaccurate color bleed. I use higher negatives for faster renders but for final renders you want to have your Min value at least -3 or -4, and your Max value at 0. I use Min -6, Max 0 (or -1 if I'm feeling lazy and don't want to wait). The adaptive method used optimizes after each itteration only calculating the parts it needs to refine.
10 HemiSamples is *really* low for this kind of scene and you will notice blotchy areas or graininess if your interpsamples is also too low. 30-50 is much better. Like I posted above QMC Depth is the number of times the light bounces so 3 means you only get two reflections and light will not pass through more than one object because it will end on the second object (3rd surface). Really for a scene like this you need transparent shadows on and a QMC of at least 6. 8-10 would be even better if it doesn't slow your render time to much.
The problem with a higher 2nd bounce is that it washes out your shadows and shadow detail. I would try lowering the 2nd bounce back to 1.0, try to get the light bright enough with raising the first bounce.
I'll do up a sample render too.
-Jack. |
Post by Jack Edwards // May 25, 2007, 8:30pm
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Jack Edwards
Total Posts: 4062
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Ok I whipped up a scene with some primitives that is similar to yours.
Here's the light/shadow test before materials:
6389
63906391
Edit: forgot to mention that I ended up using two spot lights. One white and one gray.
I'll add materials and re-render. Posting material settings, too.
-Jack. |
Post by Jack Edwards // May 25, 2007, 9:03pm
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Jack Edwards
Total Posts: 4062
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Basic textures:
6392
Turn on transparent shadows:
6394
Turn on caustics and set Factor to 14.0:
6393
-Jack. |
Post by Jack Edwards // May 25, 2007, 9:15pm
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Jack Edwards
Total Posts: 4062
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Here are the materials used:
All the glass was this with different colors:
6395
The Cube/ball was this:
6396
The cone was similar with the reflectance higher and the diffuse lower
The blue ball was this:
6397
The ground was this:
6398
Hope that helps!
-Jack. |
Post by kena // May 25, 2007, 9:38pm
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kena
Total Posts: 2321
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ok then, something is wrong here
When I set my Vray up like your's, it is just too dark - I even tried making the light a brighter white and that did nothing.
When I tried making the Sample Size to 0.020, it defaulted to 0
Testing, if I did anything less than .5, it defaults to 0 and if I do from .6 to .999, it defaults to 1.
6399
640064016402 |
Post by Jack Edwards // May 25, 2007, 9:52pm
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Jack Edwards
Total Posts: 4062
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My guess is the difference is the ground plane color. Try a light grey and see if that brightens things up. Then go back to the blue and try upping the first bounce value. For my fan scene which was mainly indirect light, I had to set first bounce to almost 5.0. Also I did end up using two spot lights to give the shapes a bit more definition in the scene above.
The sample size is specific to lightmaps so if you're not using lightmaps then changing the value doesn't have any effect.
Edit: BTW... how far are your spotlights from your scene? If they are set to exponential attenuation the light will fall off fairly quickly.
-Jack. |
Post by kena // May 25, 2007, 10:02pm
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kena
Total Posts: 2321
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I tried setting first bounce to 15, and it didn't make a difference.
If I make the Min.Rate -2 and the Max.rate -6, then this is what I get after 5 prepasses.6403
now off to bed - I'm already a couple of hours late :D |
Post by Jack Edwards // May 25, 2007, 10:51pm
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Jack Edwards
Total Posts: 4062
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Whupps... I forgot. That's a bug in the 7.5 release. The Min and Max are backwards, sorry! :o As long as you're getting multiple passes then you have the values right. ;)
-Jack. |
Post by kena // May 26, 2007, 6:35am
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kena
Total Posts: 2321
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ok - that makes sense. is the sample size thing also a bug?
1 spotlight
6408
2 spotlights
6409
settings are like those above |
Post by Jack Edwards // May 26, 2007, 5:24pm
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Jack Edwards
Total Posts: 4062
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This looks about done. Huge improvement over the earlier ones and looks like you're definitely getting the hang of VRay.
Not sure about the sample size thing. I haven't noticed any problems with it, but I don't think that I've tried to change the sample size either. Have you tried doing any renders using lightmaps (in the secondary GI)? I've found they help with evening out the caustics and seems to give better results for situations with a lot of bounced light. Much longer render times though.
-Jack. |
Post by kena // May 26, 2007, 6:05pm
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kena
Total Posts: 2321
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lol - then trying lightmaps will just have to wait until next week... I'm on my laptop at my parent's house now... here for a holiday weekend. I have the installer, but no way could this poor thing match my dual AMD desktop for rendering ;) |
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