Reflection Problem

[Michael Pickard]

Hi,

 

I've been rendering out a bathroom but when i set up a render close up, in the mirror some of the reflections dont seem right.

 

If you look at the JPEG attached:

 

1. The blinds seem to be skewed

2. The reflection seems to switch halfway up the tap.

 

What could be causing this.

 

Could it be something to do with the UV's, materials or is it meant to be like this.

I have looked at references to reflections in mirrors and it doesn't seem to happen to that extent in real life.

 

Any advice would be great.

 

I've also attached the materials used.

 

Thanks in advance

 

[SkylineArch]

I would look at the geo itself first. Might be a smoothing issue.

[Tom Sproule]

I would look at the geo itself first. Might be a smoothing issue.

 

I have to agree.

 

Looks like a chamfer has been put on. If so you can change the options from 'smooth entire object' to 'smooth chamfers only'. If you can't do that, try adding a smooth modifier but leave 'auto-smooth' unchecked. That should fix it.

 

Best, Tom

[Larissa Holderness]

I get this sometimes ... especially when I get crap geometry from architects. Try deleting the faces that are causing issue, and remodel them. Of course, try the smoothing thing first.

[Michael Pickard]

Thanks for the advice.

 

I had a turbosmooth on he mirror which seemed to be causing the distortion in the reflections so as suggested i removed that and used the "smooth chamfers" instead which has solved the problem thanks.

 

The tap is still an issue. I also had a turbosmooth attached to that which was causing some distortion but by doing "smooth chamfers" it still is having a problem. I've also tried the smooth option but that still doesn't look right.

 

Also without the autosmooth modifier all the edges still seem really sharp.

 

I've attached some Jpegs to show you which each does.

 

I've also tried to remodel as suggested by Larissa but that didn't seem to help.

 

Any more ideas?

 

Thanks again

 

[Michael Pickard]

Also I'm also getting some weird noise in my image. See attached image.

 

It seems to of happened when playing around with the F-number on the camera as i needed it to be brighter. But by adjsuting it, its created noise.

 

Any advice on how to stop this?

 

Thanks

 

[Francisco Penaloza]

If your model comes from any CAD solid modeling software you should not use turbo smooth or similar. All those geometries get triangulated as a mesh, not a polygon and those are not friendly with any "automatic' smooth solution inside Max.

 

To have a correct auto smooth you need to have a Polygonal modeled mesh with quads aligned and marking where are the areas of smoothing.

There are several tutorials online how to do this.

 

If I don't have time to remodeling that piece I would first weld all vertex, rebuild the smooth group inside the mesh, check normals and then use the edge text VRay shader in the bump channel to create a small chamfer effect.

 

Now if your shot will be as displayed here, I would recommend you to remodel that faucet to effectively produce all those chamfers effects.

 

Regarding your Noise, it is all about samples, F-Stop does not have any contribution to that noise unless you are using DOF.

What it could happen is since your image is getting brighter, it may be displaying the lack of sampling that maybe before was not noticeable because it was darker.

[Tom Sproule]

If I was you I'd leave the turbosmooth on, I think it looks pretty nice with the distortions in the metal. It looks pretty good. You can do it with chamfers, but I am not sure which version of Max you are using. My chamfers has an option under the 'Input Options' roll out which says Min Angle and Max Angle, and you can set which angle you would like the chamfers to occur on. It might be easier to do it within the Edit Poly, if you select the edges you need chamfered and then chamfer them that way, instead of with a modifier.

 

I'm not really sure on the noise, which noise you are referring to as I'm not sure how it should be rendering.

 

Best, Tom

[Michael Pickard]

Thanks for both of your replies.

I will see how much time i have at the end to see if I remodel the faucet.

 

The noise is on the tiles on the walls. It should be a nice smooth glossy material but it doesn't seem to have it.

 

Could it me i need more light within the scene?

[Tom Sproule]

Hi Michael,

 

It could be the lighting or the material. If you are using a bitmap in the diffuse slot and the bitmap isn't high enough resolution, you would get noise. For the lighting it would most likely be the subdivs. Which version of V-Ray are you using? Are you using an HDRI?

 

Normally to eliminate noise in a render you open the Render Setup and under 'Bucket Image Sampler' you adjust the Max Subdivs box and the Noise Threshold. Also you can get noise from the way lights are being calculated under 'Global Switches' rollout.

 

To start with adjust the Max Subdivs to 24, adjust the noise threshold to 0.05 and adjust the Goldbal Switches from 'Probalistic Lights' or 'Adaptive Lights' to 'Full Light Evaluation'. Some swear you have to keep probalistic or adaptive on or say you should, but from my experience it can introduce noise to the render. The reason for this is one area of the image is using certain lights to calculate the lighting and an area next to it is using different lights.

 

My earlier question about HDRI's was because if you are using an HDRI I would adjust the subdivs on the HDRI light to 32, that should help eliminate noise. I know that with the new versions of V-Ray the subdivs are supposed to be automatically changing depending on your noise threshold, however, in practice I've noticed the subdivs of HDRI's are not automatically modified and so to eliminate noise caused by HDRI's you have to adjust the subdivs in the light itself. I imagine the reason for this, I'm not sure, but I guess, is because the noise is caused by the HDRI map and not the light and so the light cannot adjust to eliminate noise.

 

For earlier versions of V-Ray the subdivs in lights are not automatically adjusted by the noise threshold and you will need to adjust each light manually - 16 or 32 should be enough.

 

If you discover that under the 'sampling' rollout the subdiv option is greyed out, then open V-Ray Light Lister and adjust the subdivs there. The V-Ray Light Lister is either in your V-Ray toolbar or under the 'Tools' drop down in your main toolbar.

 

I hope this isn't too confusing and is of some help.

 

Best, Tom

[Michael Pickard]

Hi Tom,

 

Thanks very much for all your advice. I was indeed using a HDRI light and uped the samples as suggested which actually seemed to help.

 

I also used a combination of the "vray denoiser" and played around with it in Photoshop.

 

I ran out of time on the project overall so didn't have time to go back and fix the issue with the tap but overall am happy with the way it has turned out (See attached)

 

Thanks to everyone who commented and gave advice.

 

Michael

 

[Tom Sproule]

Hi Michael,

 

Great, the image looks really good.

 

I'm glad the advice was of some help.

 

All the best, Tom