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as we can't mix a sun with hdri, I make two render one with the hdri and the other with phys sky and mix them in photoshop. No need a high sample image for the phys sky one sample 12 is enough.

Hello rickinmotion,

If you need the direct contribution of a Sun plus and hdr skydome, I also recommend you this workaround:

- Create an squared plane (9m x 9m) and apply an emitter material to it (1000000 Watts and 5777K color). You can apply a round mask to the whole material if you want to ensure its round shape.

- Put the emitter 1km away form the center of the scene. These proportions (9m side and 1km away produce the same sun aspect and size than the actual sun diameter at the actual distance).

- Parent the sun object to a null locator in the center of the scene just to be able to rotate the sun freely.

This way allows you to get the result you want (custom sun + hdr lighting), but the benefit is that you get it in the same render time (no need to launch a different render and then compose them).

In addition, you can enable MultiLight and thus have custom control over the hdr and sun intensities separately.

Even more: if you enabled Color MultiLight (take care of your Ram consumption), you could adjust the sun color as well.

And all of this in one render ; )

I hope this were helpful.

Greetings

Dario Lanza

Thanks for this helpful workaround.
But why not integrate this in the next release of Maxwell

Nice technique, thank you for share

Thanx

Hi Dario,

nice info, cheers.

What Efficacy would you suggest using on the sun light?

cheers,

Steve

That is a nice tip, but it doesn't take into account atmospheric conditions (only the sun disk itself) so things like the "sun halo" effect do not appear... so it really is only appropriate for space renders (where there is no atmospheric scattering present).

Best,
Jason.

But halo will be visible from HDRI most probably, usually it's not clipped by camera when taking photo.

If all you are trying to do is add back contrast (strong/sharp shadows) to a poorly made HDR then editing it in Photoshop is faster and easier by far. This technique makes the most sense in IBL where the sun is completely hidden from view( cloudy day, etc.) and you want to inject a "sun" into the scene. However without atmospheric scattering to soften/diffuse the "sun" you will get a result that is far too "contrasty" -- yielding ridiculously unrealistic hard shadows... except for a space render (which I do from time to time) where this technique is very helpful

Best,
Jason.

My old solution is here

Just hole for HDRI dome


direct Sun lighting


HDRI lighting


Final lighting with Multilight

Yes, that's a much more natural looking solution

Here are some renders to show what I mean -- I used the default physical sky which is going to be as "contrasty" as the sky will ever be (much more so than a cloudy day), and even here you can easily see the that the disk solution is harsher and artificial looking... now you could fiddle with multi-light to get the color and intensity to be a closer match for a particular time of day. However at the end of the day the disk solution takes twice as long to render (than Physical Sky Sun) and is not nearly as natural looking.

Disk - Noon

Sun - Noon

Disk - Morning

Sun - Morning


With effort it could be made to be OK in certain circumstances but the old solution(post above mine) is generally faster and more natural looking.

Best,
Jason.

The other solution and works great as well is using hdrlightstudio 4 with the sun shade function
my 2 cents for this thread

I do it a bit different - for interiors esp.:
1 render with sun - no glass in windows
1 render with sky dome (no sun) and glass in windows
merge it and you have physical sun with "ambient occlusion"....

I do it very easy.

1. I make a sphere for my skydome and apply my sky pano mxi (or hdri).
2. I apply the Maxwell tag "hide from GI" to the sphere (skydome).
Bingo - I have sun that enters the sphere and thus have the Maxwell sun in my scene.
Everything can be adjusted with multi-light as I do it even with the standard sun/sky anyway.

I only use the fake sun method when I want soft shadows...this is when I make an array of spheres to give a soft shadow effect like when the sun is passing over some clouds. I use the 5777k temperature also for daytime scenes but this value gets a bit tricky when you want the sun closer to morning/dusk because that value is not good any more an you have to lower/tweak your temperature value. Render times also seem to be much higher than using the Maxwell sun.

I apply the Maxwell tag "hide from GI" to the sphere

This is a mistake, it does more than just let the sun through, it also stops the lightsource from contributing to second bounces (in recesses and corners) best to avoid such hacks, and also bear in mind that if you hide to gi you also need to hide from ref, if you want a correct render.

Dario has correctly recommended the best technique, he omitted to mention that you need to choose an appropriate hdr and align it, prob because thats quite obvious and didnt need saying. The other technique which is quicker but less flexible is just painting/boosting the sun spot in PS, as has been mentioned.