VrayHDRI problem

[reptar]

Hi, I have an exterior scene. I am using a daylight system using VraySun and no skylight within the daylight settings.

 

I have a HDRI image which is not working. I have two attached images. One is GI Environment (skylight) override checked, the second image has this option unchecked. Both images are identical in terms of lighting differences. The sky appears black when it should be blue. I am using an irradience map and light cache both multipliers set to 1.0. My antialiasing filter is Catmull-Rom.

 

In the Vray Physical camera view i can see the HDRI image as the background and in the material slot it is set as a spherical environment, overall mult: 1.0, Render mult:1.0, Gamma:2.2.

 

Please let me know if there are any settings which you would like which may further determine why the HDRI image is not working when i render.

 

Thanks

[Stephen Thomas]

If you're using the physical camera you will need to adjust the multiplier of your HDRI to compensate for the exposure of the camera.

[reptar]

Will enchancing the intensity of the HDRI cause the HDRI reference to be washed out white or is this where the high dynamic range come in. In material editor the HDRI looks completely white, is this normal? What is a reasonable intensity increase value?

 

Thank-you

[Stephen Thomas]

I assume you're using the HDRI in conjunction with a Vray Sun, is that correct? Since the Vray Sun intensity is around 100 times brighter than a typical light you would use with a standard max camera, your Vray Physical camera is exposed for this. You then have to boost the intensity of your HDRI to a level which is comparable to this very bright direct light source, typical values might be around 20-30 depending on the HDRI that you're using.

 

And yes, the HDRI will now look completely over-exposed in the material editor.

[Stephen Thomas]

Also, I assume that when you say the Environment Override is on that you have dropped your HDRI Map into the slot and not just using the colour swatch?

[reptar]

yeah i placed an instance into the GI Evironment slot.

 

Boosting HDRI intesity to 30 seems to be working nicely. Thanks again.

[ruskie77]

as a quick and dirty set up, I have a dome light with a HDRI texture map (multiplier to 1)

 

a vray sun with the sun intensity set to 0.01 Or 0.015

 

a vray physical camera with...

 

f-stop 5.6 or 4

shutter 1/20 second

Iso: 100

 

that gives fairly sensible results.

 

I like to keep the dome light at multiplier 1 and the sun 1% of the "true" value, that way, you're not messing about for ages balancing fill lights and "normal" multiplier values work quite well.

[reptar]

Excellent, i'll have a go with these suggestions.

 

Thanks