Render: live view is much better than doing a render with excellent level

[Anonymous]

So I have this problem since 4 weeks now, I did few HDRI 360 environnement for a model and I am only changing the decals from one to another. 

When I am working on a model, I can see the reflexions and shadows and also a nice level of quality. But when I do a local render, it just remove these 2 things so I am forced to just make a screen shot of fusion instead of using the render module. Thank you for your help

[Phil.E]

Hi,

Thanks for posting and asking. It appears that the HDR image you are using is extremely large. This is overloading the memory buffers in the render environment. Try using a smaller size version of that image, i.e. try 50% reduction in size.

Thanks,

[Anonymous]

Thank you Phil !

I just exported a new .exr environnement with 50% the size of the first, and run the same comparaison test, unfortunately this have not solved  the problem as you can see in the 2 images, the live view is nice and the rendered model is ugly. I cannot understand that the rendering process cannot gives an image at least as nice as the live view, and this is not about the machine, I am swiveling full speed around the model and it always look nice with perfect reflection and shadows, but everytime I do the render, it turn it ugly. Thank you for your help !

[Phil.E]

Can you share the model again with the smaller HDR? I could not use your original file without crashing because of the HDR. 

From what I see the custom HDR does not have a single light source. If you expect hard shadows, you need a light source like you find in the dry lake bed environment that is included in Fusion 360. Otherwise, it's like a cloudy day, the light is diffuse and the shadow is too.

I need to test your file a little to try to bring out the reflections.

[Anonymous]

The shadows and reflections are always on point in the live view, this is not a problem. 

When I render, the surface become flat, low res, no shadows and no reflection, it,s like the render process isnt working at all, but the look in the workspace is absolutely perfect (except for the edges and some part of the model are not completely rendered). 

I tried to include the project with the smaller HDRi but the 50% still do 343 mo

[TrippyLighting]

The reason for this may not obvious, but the lighting in the live view is not based on the HDRI, which is used to illuminate the scene when rendering. 

The HDRI you are using for rendering has a mostly overcast sky which leads to the flat look.

I'd pick another HDRI, perhaps from HDRIHaven. 

[Phil.E]

Thanks. 

I'm finding that the decal image itself is blocking any reflections. In the live view Fusion is showing you reflections on the underlying material, it does not compute reflections of decals in the live view, the decal is ignored for reflections.

I'm not sure how to make a decal image "reflective", but I'll look for an answer.

Regarding shadows, in your new file the light source is diffuse. It's a morning sun behind trees. You can see several places in the image where the natural shadows are diffuse. The rendering results are the same, so the lighting is correctly computed. 

Why do you see harder shadows in the live view? Because they haven't been computed. That's what rendering does, it computes the lighting. In the live view, it's approximate, and the hard shadows help you find the direction of the light source. Once rendering starts, it computes the light rays that would actually exist, aka, ray tracing.

Find an HDR that has really strong shadows if you desire really strong shadows.

Thanks, let me know if you have more questions.

[Anonymous]

Thank you Peter, 

But I am 100% sure that the HDRi that I made is just perfect, actually the shadow is just behind the model so this is good and Fusion have recognize that even if it's overcast, the light comes from the sun wich we can see if we rotate the view. Plus, using different HDRI is not an option as I am doing multiple model designs and different decals depending on where the station will be, and the same problem occurs no matter if it's 100% sunny or cloudy. Actually Fusion is impressive at recognizing the environnement and doing the shadows and reflection, in the live view, but when I do the render, all of the good looking things are off.

Please have a look at the screen shot made in the live view, we can see the shadow it's looking good, and it's just the right shadow for the hdri source. But if I do a render, all of this is gone, please have a look at the images

[Phil.E]

The way to control decal reflectivity is to turn it into an appearance texture.

Here's a post about it:

https://forums.autodesk.com/t5/fusion-360-support/how-do-i-remove-the-glossiness-from-applied-decals...

And a screencast showing how:

https://knowledge.autodesk.com/support/fusion-360/learn-explore/caas/screencast/Main/Details/8597e56...

[Phil.E]

The live shot you just posted shows the shadows of the environment perfectly. The sharp shadow is incorrect for this lighting environment.

If the live view was correct, there would be a hard line where the building cuts a shadow, same as the box.

[TrippyLighting]

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@Anonymous wrote:

Thank you Peter, 

But I am 100% sure that the HDRi that I made is just perfect...

---

What I explained is the result of almost 3 decades of professional experience in computer graphics, CAD 3D modeling, and rendering.  You simply are incorrect!

[Anonymous]

Hi Phil, 

I understand what you mean. I would like it to be the thing but I have 7+ other environnement where this is not applying correctly, please see this model, the live view is perfect, then the render is super ugly and no shadow, 

note: for the render, I am using local + excellent, 

[Phil.E]

The reason may the size of the hdr. That one is immense, 18888 x 9444. Try a smaller version of that hdr, does it render differently?

[Anonymous]

Peter, please have a look at my message #12, with the 3 images, the HDRI is a pure sun, in the render, there is simply no shadows, why ?

[TrippyLighting]

Here are my attempts using the Plaza HDRI, which is one of those provided with Fusion 360.
It has a bright single-source light source - the sun - and is cloudless.

This is the viewport display:

 

This is the render:

 

This is perfectly in line with what I expect for a PBR render engine to deliver. Shadows are still somewhat blurry because there is a lot of haze (Mie scattering) in the air causing the light to diffuse.

If you use this HDRI, which was taken in a natural setting away from urban pollution then you'll get razor-sharp shadows.

 

 

[Anonymous]

Thanks again for your assistance, 

I just wrote a long reply but autodesk bugged and I lost everything. 

In short, I tried the Plaza one, with flatten ground and no flatten ground. There is a patch of red and green that appears on the model at each render I don't know what cause this issue. 

Also I tried an HDRI with bright sun to see and the issue is still there, I also checked the flatten ground box but his option distord the sphere behind and make it ugly, plus I cannot hide the tripo in the hdri so I cannot really check the flatten ground box. 

[Phil.E]

The graphics team helped out with this one, and thankfully so. Their comment was: 

"... you could adjust the gamma of the hdr file. The sun could be brighter and sky could be darker. (attached). The sky lit the ground so the shadow is not obvious."

So apparently the HDR settings make a big difference in how shadows are created in renderings.

[Anonymous]

Thank you Phil, 

I tried your ''reduced'' .exr, the shadow worked fine. Where did you adjust the gamma ? Because I would like to replicate on my hi res hdr, 

I will go and redo the hdr at this place and seek for cloudless condition, it not nice enough without shadow. 

One more problem is the ''flatten ground'' situation, as you can see in the first image, the flatten is checked, but it always distord the hdr bewind in an ugly way. Is there anything to do about this ? 

Thank you !!!

[Phil.E]

Flatten ground will necessarily do that. It's better to render without it. I've never found myself doing a rendering and needing flatten ground, so perhaps I'm not the right expert for that question.

The image was edited in an image edit program outside of Fusion.