HDRI too close? Alternative fix?

[Morne]

Hi all

OK I have a weird question. If I stick a HDRI in my dome light, how can I make the environment or the radius of the dome "bigger"? Imagine for a second a sphere surrounding your scene to extents (this sphere represents the extents of the dome light). Say for example that sphere has a radius of 400 meter. Now the only way to see a lot of that dome with your camera is to make your view angle very wide (focal length of about 22mm or even 18mm seems good). However I rarely go less than 28mm. But with 28 obviously the lense is not as wide and you get less of the sky and the sky seems zoomed in too much. If I can leave my camera at 28mm and instead increase the 400 meter radius of the dome light to something like 10 000 meter, the environment will look more correct and I will see more sky

(Yes I know the domelight isnt 400m radius, it was just an example to try and explain what I mean)

[Morne]

Anybody?

Can this be done or not?

(Hate to bump my own thread but its kinda urgent)

[Mokiki]

I dunno where but I think vlado once said that it as of vray right now it can't be changed. I think your best bet would be to actually create a sphere and map the hdr to it or ad the sky in post. But I agree changing the "size" inside the domelight would definitaly be a timesaver

[chriserskine]

your not changing the fov when you change the dome light radius.

you'll have to use wider angle view and move the camera closer if you want more sky.

I probably use between 14mm and 24mm for 95% of my arch viz work.

[Morne]

your not changing the fov when you change the dome light radius.

you'll have to use wider angle view and move the camera closer if you want more sky.

I probably use between 14mm and 24mm for 95% of my arch viz work.

Yes but those wide angles are fine for standalone buildings etc. When you work with large buildings up close then those wide angles distorts the edges too much.

As Ralph mentioned, currently I use a sphere with the image applied, and if I need to see more sky I just increase the radius of the sphere WITHOUT touching my camera. Would be nice to be able to do this with and HDRI in a dome light!

[Dave_Wortley]

If you create a Sphere, with about 6 segments, Set the Hemisphere Value to 0.45, then add a turbosmooth with 2 itterations, add a UVW_Map, Spherical. You can then apply a VRayLightMtl to make this your reflector/illumination dome. A good trick here is to apply a Shell Material, and to put your VRayLightMtl (with a VRayHDRI map set to 'Standard 3dsmax Mapping')in the Render slot and a Standard Self Illuminated Material in the viewport slot with the same map as a max bitmap, this way you'll be able to tweak the UVW Gizmo and see what happens in the viewport and get the same at render time without having to switch materials. Play with the scales and the hemisphere values and the UVW position to shift how much of your reflection becomes weighted to ground or sky.

[Morne]

If you create a Sphere, with about 6 segments, Set the Hemisphere Value to 0.45, then add a turbosmooth with 2 itterations, add a UVW_Map, Spherical. You can then apply a VRayLightMtl to make this your reflector/illumination dome. A good trick here is to apply a Shell Material, and to put your VRayLightMtl (with a VRayHDRI map set to 'Standard 3dsmax Mapping')in the Render slot and a Standard Self Illuminated Material in the viewport slot with the same map as a max bitmap, this way you'll be able to tweak the UVW Gizmo and see what happens in the viewport and get the same at render time without having to switch materials. Play with the scales and the hemisphere values and the UVW position to shift how much of your reflection becomes weighted to ground or sky.

Yes I know all this and as mentioned I'm doing it currently. The question however is if it is possible to simply modify the dome light some way...

[Dave_Wortley]

http://help.chaosgroup.com/vray/misc/

VRayDomeEnv - Try this... You can do some positioning/scaling with it but I don't like the workflow it requires...

[Morne]

http://help.chaosgroup.com/vray/misc/

VRayDomeEnv - Try this... You can do some positioning/scaling with it but I don't like the workflow it requires...

I checked the readme for that, and I agree with you, that SUCKS. I'm sure others will find it helpful for other situations, but this isn't one of them

[Svetlozar Draganov]

It is not possible to change the radius of the VrayDomeLight - there are a few approaches that could help in this case.

The most obvious one is to use VrayDomeLight for illumination and create additional bg-sphere with the same texture inside VrayLightMtl and adjust its scale and position as you like.

As a second approach you could add some tilling to HDRI image in order to adjust needed size.

And of course you could make DomeLight invisible , and use the same texture in EnvironmentMap slot which could be manipulated via Bitmap parameters.

[trixian]

Firstly, if I have completely misunderstood this discussion, please ignore.
The domelight, and environment are represented as infinite spheres, so size does not matter. There is however a node still not included in Vray's default installation called "VrayDomeEnv" that you can get from the spot3d site as a separate download. You then plug your hdri into this map and set the parameters accordingly (though the spinner names are confusing and the documentation is rather lacking last I checked).
This will let you bring some sense of scale and "floor" into your dome environment, but you will still need to play with your camera's FOV to get more into the frame if needed.
This does not necessarily work so well with all hdri images, mainly ones where the environment in the image is evenly distributed around the image with similar distances. A large tree in the middle-ground/foreground will most likely look bad.
That said, mapping the image onto geometry replicating what is in the image is usually the best way if you need to retain some illusion of depth and scale (more pertinent for interiors).