Dots on everything using HDRI (strange?)

[handige_harrie]

That's caused by too low radiosity settings.

Try raising the min and max resolution settings (10-20 might do).

Btw are you Dutch? Martijn is a typical Dutch name.

Ik ben iig wel 'Dutch' ;).

[killer397]

Hi i tried raising my min and max resolution to 100 - 200, But it gave me almost a similiar results.
I had it on 50 - 200 first and when i lower them, all i get are dots everywhere.
Here's another render with min 100 and max 200 resolution under the render settings (radiosity), took me about 7 minutes to render.

http://members1.chello.nl/f.merckelenbag/dots2.jpg



Hehe ja ik ben 'Dutch' :)
Leuk om er nog 1 te zien hier op het forum :)

Greets, Martijn.

[dandavis]

Looks like maybe you're using Stochastic radiosity settings?? It always tends to make things grainy like that. OR perhaps you need to increase the accuracy?

[Aries]

Using a sphere with Hdri on it ?
Try with Sky object..
Closing the scene with spheres is not that good .. apparently :)

[killer397]

Hi there and thnx,

Dandavis: no i didnt use Stochastic mode :)

Aries: yeah i used a sphere, 2 actually.
1 GI and 1 Visible.
what do u mean by sky object ?

Greets, Martijn.

[AdamT]

As a general rule, when HDRI is your only light source you have to raise your samples a *lot*. What settings did you use for the render?

[Per-Anders]

you have too high ming and max settings with too low samples

you need to increase the number of samples relative to the min/max settings, i would drop the min max down to 8/30 even and then get the samples up to near 600

if you have very high min/max settings (over 50 for min is high) then you will get a look very much like stochastic rendering. as each point of sampling will be very close to teh next point of sampling, there wont be space to actually blend this smoothly between them if htere are differences, differences will be caused by having too low a number of samples (the higher the number the more consistent and accurate the result).

[killer397]

Hi there and thnx again.

I got almost excactly the same results with the other settings i tried.
When i lower my min and max resolution it gets alot worse.
Here are some pictures of my settings:

Radiosity settings:
http://members1.chello.nl/f.merckelenbag/radiositysettings.jpg

Visible sphere settings:
http://members1.chello.nl/f.merckelenbag/visiblesettings.jpg

GI sphere settings:
http://members1.chello.nl/f.merckelenbag/gisettings.jpg

and here is the picture with these settings:
http://members1.chello.nl/f.merckelenbag/dots3.jpg

I get the same results using another hdr map.

Greets, Martijn.

[Per-Anders]

as said before, it's the samples. your number of samples isn't reflecting the min/max settings.

i.e. to get smooth with a low min/max settings (3/20) i use at least 650 in the samples settings, so looking at where you are right now you need to have around 21500 samples to get totally smooth results, that's going to be totally prohibitive, then of course my seetings are for a diffuse depth of 1, so you have to multiply up the samples again for an increased diffuse depth.

my suggestion for good *fast* settings

accuracy 70%
diffuse depth 1
samples 800
min 3
max 20

that should get you a "smoother" result, though it won't have as much definition in the shadows, but moving from there you should be able to gett good results.

[Aries]

It's all about dimensions... or something like this :)
(Try with some fixed radiosity settings to modify the sphere's diameter)
That's why I found Sky object more usefull for "compact" scenes..

About the downloaded scene..
Try with:
- stochastic samples: 600
- min: 300
- max: 6000

Work's here..

Good luck

[killer397]

Thnx Aries these settings worked fine.
But what do you mean by Sky object ?
Where can i find it ?
Im pretty newbie to this soz.

Thnx, Martijn.

[Aries]

Glad .. :)

Sky object it's in Objects/Scene/.. Sky (no more then 1 sky object in the scene)
Works fine with Floor object too. (that's an infinite "ground" object, non editable)
Anyway.. apparently min, max are linked to object dimensions.. if you see "big" samples in prepass you need to set bigger values for min, max... (but i don't know the theory.. just what i found)

Good luck..

[killer397]

Hey thnx alot for the tip.
With the sky object it looks very different now (alot more in the direction that i wanted).
Here's an Example:

http://members1.chello.nl/f.merckelenbag/testhdri1.jpg
Rendered with settings:
- 2 sphere's one GI and one visible.
- Accuracy: 70%
- Diffuse depth: 1
- Stochastic Samples: 600
- Min.: 300
- Max.: 6000



http://members1.chello.nl/f.merckelenbag/testhdri1.jpg
Rendered with settings:
- Sky object
- Accuracy: 70%
- Diffuse depth: 1
- Stochastic Samples: 600
- Min.: 100
- Max.: 200


Thnx, Martijn.

[Aries]

Ah.. another thing..

Uncheck "Recieve" from the Illumination tab of Hdri material..
No need there.

Try to reduce the Min value.. too much noise on the ground.
And you need a bigger value in the Max setting i think..
Min is for flat surfaces..
Max is for details..

It's easy to see in prepass.. you need a lot of "points" under the car.

Hope this helps..

[killer397]

Thnx once again Aries.
Ive got another question though: It makes an ugle green light on my plane.
How do i get rid of it ?

Thnx, Martijn.

[Aries]

No problem.. glad to help.

Firs put a material on the ground plane..
In Illumination tab of any material you have 3 things to set for radiosity..
Generate = how much radiosity is generate by material
Recieve = how much radiosity is recieved by material
Saturation = how much color is recieved from other materials

All are 100 % by default..
You can set saturation = 50% or something for the ground.. the green cast will be reduced.. but the material still will recieve the same light intensity. (and emit too)

[Aries]

Ohhh.. just found this..

The trick with Compositing tags works with skyes too..
Then you can put 2 skyes :) one with a blurry hdri map and one with a sharp one.
Same as in the tut. from Maxon with 2 spheres..
(strange tut. anyway - in manual Sky object is explicit recommended - just checked)

And put the hdri image in Luminance channel like this:

r,g,b, brightness = 100
For Texture, Mix = Multiply and 100%

And adjust from the brightness slider only.. you can have values over 100.. just type them. You can obtain greater light intensity for the hdri in this way.. Hdri is now fully supported.

[killer397]

Thank you !
Someone told me that using a sky-object wasnt a good idea since i cant change the depth of field.........is this true or can it be set ?
And i tried using an floor object instead of my plane....but now it takes ages to render......how come ?

Greets, Martijn.

[Aries]

Dof works with Skyes too...

Lower the min, max settings.. try with the default ones.
Sky + floor and a "compact" scene = more like default settings

Good luck... :)

[killer397]

Thnx Aries.......ill try :)

Thnx, Martijn

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