Black Render - Latest V-Ray/Blender 2.65 Custom Build

[reC]

Hello !

Today I downloaded and installed V-Ray/Blender 2.65-53922 64 bit latest custom build and also installed Vray 2.3.01 for Maya 2013 standalone 64 bit and I get black render. I have all the lights and materials in order but I still get the black screen. Also I do not see the V-Ray frame buffer appear anywhere. Is this an issue with the latest V-Ray 2.3 or is there something I'm missing ?

OS : Windows 7 64 bit

[bdancer]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

Hi! Please check the wiki pages especially this step, may be it'll help to investigate the problem.

[reC]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

Hi Andrey and thank you for answering so fast !

I read through the link you gave me but I do not understand something. Should I open Blender in the windows terminal (cmd.exe) ?

The resolution that I am trying to render is lower than the maximum allowed in the demo. Mine is set to 400x200.

I will copy and paste for you what it says when I press F12 in the upper info window inside Blender.

Traceback (most recent call last):
File "C:\Program Files\VRayBlender-2.65\2.65\python\lib\subprocess.py", line 1090, in _execute_child
startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\Program Files\VRayBlender-2.65\2.65\scripts\startup\vb25\render_ops.py", line 1012, in render
err = vb25.render.render(self, scene)
File "C:\Program Files\VRayBlender-2.65\2.65\scripts\startup\vb25\render.py", line 2030, in render
export_and_run(init_bus(engine, scene))
File "C:\Program Files\VRayBlender-2.65\2.65\scripts\startup\vb25\render.py", line 1929, in export_and_run
run(bus)
File "C:\Program Files\VRayBlender-2.65\2.65\scripts\startup\vb25\render.py", line 1787, in run
proc.run()
File "C:\Program Files\VRayBlender-2.65\2.65\scripts\startup\vb25\lib\VRayProcess.py" , line 132, in run
self.process = subprocess.Popen(self.params, bufsize=256, stdout=subprocess.PIPE)
File "C:\Program Files\VRayBlender-2.65\2.65\python\lib\subprocess.py", line 818, in __init__
restore_signals, start_new_session)
File "C:\Program Files\VRayBlender-2.65\2.65\python\lib\subprocess.py", line 1096, in _execute_child
raise WindowsError(*e.args)
FileNotFoundError: [WinError 2] The system cannot find the file specified

location: <unknown location>:-1

I have also tried typing the environment variable %PATH%

I hope it makes sense ! I just want to test an interior scene out for a school project but I can't since it won't render. It shows the usual black Blender render window but it doesn't show the VFB and if I try to close the window I can't because it shows a NOT RESPONDING warning.

I hope you can give me a solution ! Thanks !

[reC]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

I managed to make it work but only after I installed Maya. Well that's good I guess considering the alternative.

Is there an up to date list on the limitations of the current V-Ray to Blender implementation compared to what we get in Max or Maya ? For instance is there a way to have an 32 bit exr assigned to a dome light for the IBL ?

[rws]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

Most features are there afaik,

For instance is there a way to have an 32 bit exr assigned to a dome light for the IBL ?

Use a Hemi light and assign texture to it, make sure to set the gamma of the image correctly (IE not srgb)

[reC]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

Hi ! Thank you for replying !

It seems Hemi light is similar to the dome light in 3ds max but I'm having difficulty in positioning it the way I want. Is there a way to make the environment texture visible in the 3d viewport so I can see how my changes affect the rotation of the map ? It's quite difficult to manage by only rotating and then pressing F12.

Also what is the best way to tweak the environment light intensity in order to get a realistic result. I tried fiddling with the lamp instensity ( I changed it from default 30 to 10 and then I searched online for measured sun intensity in W/m2(square) and it is something like a value of 1360 but that is way to much in my render )

[rws]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

The easiest way to position rotation is to keep test render on a empty layer. First note that if no rotation is applied, the center of the image will be mapped to -X direction (IE West if you consider +Y north). The rotation is considered clockwise from top view.
You can use this viewtopic.php?f=29&t=845 but it's a little fiddly.

As for intensity, just tweak the lamp intensity, or the image-map multiplier (depending how you're using the image).
If you want realistic sun brightness, calibrate your camera exposure to normal vray-sun, then calibrate the HDR/domelight to the camera.

[reC]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

Hi ! Yes ! About the light intensity I just used the vrayPhisicalCamera parameters and it seems to produce good results with default light intensity of the lamp set to 1 and no change to the texture multiplier.

I checked your link and i think it's a wonderful solution. Would it not be more apropriate to use the texture UV mapped to the inside of the dome for illumination and not do the extra step with the hemi lamp ? I was just thinking of this method for cycles lighting that doesn't support spherical mapping in the World environment settings because my environment maps are all spherical half 360.

To my knowledge using this method for Cycles at least not V-Ray would be best no ? as the emitting mesh has Multiple Importance Sampling so it can be used as a workaround to the direct World - Environment settings - Spherical that is missing currently. No ?

[rws]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

For Vray, as far as I know the only efficient way is to use the domelight/hemi.

I don't know any render engine that has intensity priority sampling for mapped textures.

[reC]

Re: Black Render - Latest V-Ray/Blender 2.65 Custom Build

It seems you are right there is no priority sampling for mapped textures in Cycles using materials only under World !