Sketchup Vray 2.0 "Bump Type Maps" explanation

[manelreig]

Hello,

 

I am using Vray 2.0 for Sketchup and I am trying to understand what the different Bump Type maps mean and when you have to use one or another.

 

I understand the difference between ?gray scale Bump maps? and ?Normal Bump maps?, but not sure when to use one or another and why.

 

I have been doing some tests with a ?Brick wall? texture. I want to use a ?Bump effect? just to give some detail to the texture. In all this cases I am not using displacement. Also in all the cases, I am using a Normal Map created from the texture with Crazy Bump and with 1,0 on the Bump texture multiplier.

 

1_The first image is the plain texture, no Bump effect:

 

 

2_This is with ?Bump?: Here I understand that Vray is using my ?Normal Bump Map? as a simple ?Gray scale Bump map?. The results are what I would expect and desire for this case:

 

 

3_This is with ?Normal Map (tangent space)?. Here I understand that Vray is reading my Normal Map. The probem here is that, as you can see in the image in the intersection of the two perpendicular faces, it looks like the map is readed in different deppending of the orientation of the face. They are like contrary between each other:

 

 

4_This is with ?Normal Map (Object space)?. Here the problem is that it changes the intesity of the light in the whole wall, but it looks like the map is readed the same in both faces:

 

 

 

AS I can only post 4 images at a time, the post continues in the next message

[Nicolai Bongard]

You can read up some of the differences here (some of the things that came up after a quick google search):

 

https://www.pluralsight.com/blog/film-games/bump-normal-and-displacement-maps

 

 

https://forum.unity.com/threads/normal-map-vs-bump-map.78622/

 

http://community.foundry.com/discuss/topic/73221/normal-map-vs-bump

 

 

I am not familiar with sketchup, but what i do know is that it is prone to produce faces that are flipped and/or double sided, and it is a pain to clean up sometimes. Flipped normals may cause some of your problems. Also, since there are different modes of the normalmaps, perhaps the one youve made in Crazy Bump is unfit for the mode youve selected?

 

In vray for 3ds max, there is a map/shader that is called vraycolor2bump and a vraybump2normal, and the names sortof gives away what they do. So if those are available, asuming the setup is similar in sketchup - what you would do is insert a vray normalmap into the bump slot, and in the vray normalmap you insert a vray bump2normal, and in the bump2normal you insert your bumpmap. What this does is basically saying "here is a bumpmap, convert that one to a normalmap for me (dunno how that magic works, but it does), then make vray understand that it is to use a normalmap as basis for the bump." Since your building pretty much consists of 90 degrees geometry, i would apply a UVW map set to box mode, and adjust the size to whatever is appropriate.

[SkylineArch]

I am not familiar with sketchup, but what i do know is that it is prone to produce faces that are flipped and/or double sided, and it is a pain to clean up sometimes.

 

Not to detract from the topic, but SketchUp doesn't produce flipped or double faces, the aritst does, same as a messy modeler would in Max, Maya, etc. If you know what you are doing, SketchUp models can be very clean. Actually, flipped normals are a lot easier to see and clean than in Max, but once you understand the basics, you should never have or create any flipped normals. Double faces are pretty much impossible to create since things autoweld, unless the models you encountered had groups that overlapped and were exploded as it was imported into Max.

 

Not trying to start anything or call you out, just letting you know that SketchUp is a different animal. I think that since it's easy to learn, and there is a free version out there that it attracts rookies who do not know what they are doing. But people who started off modeling in any other program understand what to look for and avoid.

 

Sorry, carry on.

 

For the O.P. Use normal maps if you have good quality ones, bump maps for slight textures that are not that pronounced, and displacement for things like stone or if you are viewing a surface close up at a lower angle, like that brick wall would look better with displacement vs bump. Just use the override to turn displacement off until your final render.

[Nicolai Bongard]

Not to detract from the topic, but SketchUp doesn't produce flipped or double faces, the aritst does, same as a messy modeler would in Max, Maya, etc. If you know what you are doing, SketchUp models can be very clean. Actually, flipped normals are a lot easier to see and clean than in Max, but once you understand the basics, you should never have or create any flipped normals. Double faces are pretty much impossible to create since things autoweld, unless the models you encountered had groups that overlapped and were exploded as it was imported into Max.

 

Not trying to start anything or call you out, just letting you know that SketchUp is a different animal. I think that since it's easy to learn, and there is a free version out there that it attracts rookies who do not know what they are doing. But people who started off modeling in any other program understand what to look for and avoid.

 

Sorry, carry on.

 

No worries Mark, allways good with input! As i said i am not familiar with sketchup, as in; i've only barely used it many years ago back when it was new, but whenever i get sketchup files from others they are always messed up one way or the other. You have only confirmed my suspicion; seems the architects i work with have no clue what they are doing!