How does one go about having an environment light for moving objects, especially when were NOT talking about sky etc…

What I mean is this:

Let's say I have an environment light map for a room. Then the animated object would go from one side to the other of the room and close to a wall.

If the environment map remains static it looks phoney.

Is there a solution similar to this (https://www.youtube.com/watch?v=G1EIzSGVrnE [youtube.com]) in Houdini… or could one be made without using sdk etc…

If so, could someone please point me in the right direction.

Thank you

Just model the bits you want to have a realistic integration with - the env light is a unit sphere at all times.

One way to do it is to extract the light sources (hotspots) from the hdri map using your favourite comp software and then rotopaint/erase the hotspots (light sources) from the hdri so that your hdri image does not create any hard shadows like a sun or spot would do. And then you can use the extracted images on area lights and place these lights with emission maps in your scene so that they create correct spatial shadows. This procedure is fairly easy and yields great results, give it a try.

tinyparticle
One way to do it is to extract the light sources (hotspots) from the hdri map using your favourite comp software and then rotopaint/erase the hotspots (light sources) from the hdri so that your hdri image does not create any hard shadows like a sun or spot would do. And then you can use the extracted images on area lights and place these lights with emission maps in your scene so that they create correct spatial shadows. This procedure is fairly easy and yields great results, give it a try.

A very useful technique indeed. I made a tool for lighting that does exactly that in vops. Feed in a HDR and extract the top X bright spots > builds a light at the point and looks up the intensity / colour. Used it for rendering furry creature

Rob

tinyparticle
One way to do it is to extract the light sources (hotspots) from the hdri map using your favourite comp software and then rotopaint/erase the hotspots (light sources) from the hdri so that your hdri image does not create any hard shadows like a sun or spot would do. And then you can use the extracted images on area lights and place these lights with emission maps in your scene so that they create correct spatial shadows. This procedure is fairly easy and yields great results, give it a try.

Excellent. Awesome solution

thank you so much for sharing.

circusmonkey
A very useful technique indeed. I made a tool for lighting that does exactly that in vops. Feed in a HDR and extract the top X bright spots > builds a light at the point and looks up the intensity / colour. Used it for rendering furry creature

Rob

Very interesting. I'm assuming distance and cone radius is done manually.

Wow, I didn´t know about this technique…it´s pretty interesting.
Can anyone explain a bit more on how exactly to “extract” the lights from the HDRIs…and how to place them in the scene?
I think I get the general idea, but I don´t get the specifics

You can simply crop that section of the hdr image as a square image and give some feather around the edges so that it does not have abrupt cut at the edges. Once exported this square image, paint out the extracted parts of the original image, and you will end up with two textures, a square texture with the hotspot in it and the hdri image without any hotspots. You will need to use the square texture on your area light and the hdri on your environment light.
You will have to set the distance and the cone radius manually.

tinyparticle
You can simply crop that section of the hdr image as a square image and give some feather around the edges so that it does not have abrupt cut at the edges. Once exported this square image, paint out the extracted parts of the original image, and you will end up with two textures, a square texture with the hotspot in it and the hdri image without any hotspots. You will need to use the square texture on your area light and the hdri on your environment light.
You will have to set the distance and the cone radius manually.

How do you position this properly? I mean on axis.

Is it similar to this, done in Maya?
https://vimeo.com/64957671 [vimeo.com]

Unfortunately you can not pinpoint the exact position of the area light unless you shoot the hdr using a stereo rig or independently from two different axis. You will have to place it using the visual ques from the original hdr and doing some approximation.

tinyparticle
Unfortunately you can not pinpoint the exact position of the area light unless you shoot the hdr using a stereo rig or independently from two different axis. You will have to place it using the visual ques from the original hdr and doing some approximation.

Thank you - I'm just starting to wrap my head around proper ibl creation.