in your model you must have then 3 groups and every group a material, this could be the same but also three different one's
So make 3 different groups and then try again, when is doesn't work upload the file and i will search it out for you

every face with material with bump/displacement must have his own group. No interface with other materials because then the bump/displacement will not work

For every material you need to group it, but when you group it together it doesn't work

Is the window just a plain surface ? And when it is not then you must check if you have painted both sides with the glass material. When the windows has thickness you must paint both sides.

IMHO it look likes you have not painted both sides.

Perhaps the intensity of the sun. You use a background from a hdri ?
It also looks like the position of the sun.

When you have a material you must look if it is using bump mapping and displacement. If these items are actif then you must group your surface, otherwise the material will not work with the displacement/bump.

Specialy with grass material you need to have bump/displacement. So group your surface and then add the material en render.

real gras, perhaps with the fur plugin or postpro with photoshop.
I like it so far, did you model everything self. Can you explain how you made the windows.

And i like to see a night render from this house

This has got to do with the render output, in de options. Turn the overide viewport off. And then should the result the same as in the tutorial

Very good tutorial i fixed it and it worked good.
But i have a small question about your photo's after modification result.

There everyone could see through the pool water till the bottom of the pool. How did you do that, is it the color of water or something else. Please explain me how to do that effect.

Use the standard material then there is no problem

Shine and other stuf you can add to the material editor to add a reflection or refraction layer. It is quite simple but i think you must learn the online tutorials ande there are plenty of it.

Register a the chaosgroup and there you find lots of tutorials

Perhaps you didn't aplly the material on both sides of the glas, and add the 2 sides material in vray.

Place it here as a include file

Perhaps upload the scene file, then i can look at it. And perhaps the other specialist to

Perhaps you must switch the invisible option on.

This must done in the edit light option box in sketchup

Tadema,

You render with vray, but how do you do the hedge, is it a png file or is modelled in SU

Tadema,

When you have finished Easy street, do we get left to the Lazy street like in this picture

Easy, but not so easy to modelling.

I like this piece of art, also with the frog's

When there is some much fog, i think the cottage is in the highlands of Scotland

shit Book Case is what i read when i see this case.

You design with a message, but do i like this message

YES