Rendering Algorithims - They Define What You See

[TheKitchenAbode]

There has been a lot of discussion lately concerning the placement of objects within wall cavities and how to get these to render correctly in a camera view. We have all floated an open faced cabinet into a wall and been disappointed that the wall is shown passing through the cabinet. Why should this be? The wall is there, the cabinet is there so everything needed to generate (compute) the view correctly is there. It's likely due to the Rendering Algorithms and the parameters the programmers set in order to maximize rendering times. 

 

Why spend time computing data when it is not within the cameras view, makes sense. This methodology is also applied to objects and predefined elements such as wall types. A standard interior wall type, drywall-stud-drywall, appears to have a default rendering plane, the drywall face. As such any element or object behind this rendering plane will not be computed, only objects in front are taken into consideration. This is why the wall extends into our open faced cabinet.

 

To get the object to render as we intend the rendering plane must be shifted further into the wall or better still disengaged. It's like setting the clipping in a camera view or a cross section elevation. You are defining a plane that determines what is displayed and what is to be ignored. Although Chief does not provide a specific setting for this you can with the Glass House tool see the effect. The rendering plane has been disengaged, all objects and elements are included in the rendering algorithms and as such they are visible. For speed and visual purposes they have restricted the format to monotone & lines.

 

So we do know that the capability is there. The challenge is how can we exploit this to get our renders correct. Obviously we need to somehow shift the rendering plane, but unfortunately there is no specific setting for this. Although this is true there is actually a relatively easy way to do this. For example, a standard interior wall type with 3 elements has its rendering plane defined by the exposed drywall surface. However a frame wall type with 1 element has its surface rendering plane defined by the stud face. With this wall type any object in front will be rendered correctly. Need to move the plane further back, just make the wall thinner. Need to disengage, make the frame material glass. With the Material Region tool you can now rebuild the drywall without altering the rendering plane as the polyline material will be considered to be in front and therefore rendered.

 

I am certain there are many other ways to manipulate this to our advantage. Looking forward to all commentary.

 

Thanks,

Graham

 

 

[Doug_Park]

I'm trying to understand what you are asking for here.

 

The one thing I see is the need for a way for any object to cut out a hole for it to be placed into. Pushing a cabinet into a wall. As I see it there are several desired outcomes from this.

 

1) The cabient is intended to be used as a shelf/niche/medicine cabinet that doesn't go all the way throught the wall. In this case there are questions to ask such as how is the opening going to be framed and trimmed.

2) Another case is if the cabinet goes all the way through. Which we can more or less do today using openings.

 

These aren't really rendering algorithm decisions so much as how is the model going to be built decisions.

 

One problem that occurs with the rendering algorithms is when surfaces are forced to intersect each other our algorithm won't compute lines for the intersection correctly in all cases. Which means possibly some fixup work in layout. This is done primarily because the computation is very costly to do 100% correctly and it is also felt that because in real life we don't have the luxury of having two objects occupy the same space at the same time it is viewed as a model deficiency.

 

I'm not sure I'm helping here. Just trying to better understand what you are getting at.

 

Thanks.

[TheKitchenAbode]

You are absolutely correct Doug. There is a lot going on as to how objects & elements are being treated, rendering is only one of many considerations. My comments were not intended to imply there was anything wrong with the software. It was just to provide some possible insight as to how the rendering is being dealt with. I believe that this may be useful in cases where rendering is the primary objective. As with any of these manipulations one must always check thoroughly to ensure that any negative side effects are acceptable. As you indicate, forcing or using elements outside of their intended use will most likely result in unforeseen consequences. The most significant are likely the framing computations and the material lists as an example. I strongly recommend that users utilize the appropriate built-in tools wherever possible to ensure plans & designs are of highest degree of consistency and integrity. These manipulative techniques should only be used as a last resort.

 

This is purely conjecture on my part but I suspect that when one uses a predefined element such as a pass-through, door, window, etc. placed into a standard wall type that for rendering purpose the algorithms (software) see these as special items in order to adjust things so the wall surface does not extend into them. Possibly my use of the term Rendering Algorithm may be to blame for any misconceptions. Somehow out of all of the detail within a plan something has to determine what is to be rendered and what will not be rendered. To compute everything in its entirety, visible or not, would not appear to be the most efficient way to do it.

 

Graham

[glennw]

I really can't see this as a rendering problem.

 

All we need is the ability to insert an object into a wall and determine how what wall layers are effected by the insertion. 

Much the same as a Material Region can cut surface layers in a wall - we need to be able to cut into a main or framing layers when inserting objects into a wall.

[country]

I agree with Glenn. I would like items, such as a fireplace insert, to properly insert into the front wall and leave the back wall or material to stay where it belongs with proper framing around. The 3D should then be able to show the item if the other material is removed for the insert.

[TheKitchenAbode]

We are all in complete agreement on this. Unfortunately there appears to be no global way to handle this. One must first create an opening using say the pass-through tool, place the object into the opening and then go to the other side of the wall and patch it with something. I usually just float in a partition set to the same material and thickness of the finish. You would need to test this as it may have a negative effect on material lists or some other function you require.

 

There are some other work around methods described in recent posts on wall niches. But they also have limitations and some negative impact on other automated functions.

 

I was hoping that there was a setting in Material Regions tool that would allow you to toggle on/off the wrap around an opening function, but apparently this is not available.

 

Looks like it's up to the programmers.

 

Graham

[AriseDesign]

Better stairs, auto updated elevations and niches seem to be the most requested features for X8 - I could not agree more

[Joe_Carrick]

Those of you who want to place a Niche in a wall - download the "Hole in the Wall" Library Object I posted.  This will cut a hole in the surface of any wall and you can then place your niche, cabinet, or whatever in that hole.  You will need to "Frame" the wall so that it appears hollow.

[TheKitchenAbode]

Hi Joe. Saw that last night in your posting, will definitely give it a try. Thanks for sharing.

 

Graham

[TheKitchenAbode]

A method for users that do "Not" require framing details.

 

Change framing material definition to "Glass", "100% Transparency".

Float any object into place.

Use "Material Regions" to reconstruct finish around object.

 

Graham

[Doug_Park]

Graham,

 

I think my confusion is your use of the term rendering.

 

Generally rendering is used to describe the process of taking a 3D model and producing a 2D representation of that on the computer screen.

 

We use the word model or modeling to describe the items that you are talking about.

 

We use rendering or rendering technique to describe different ways of producing the 2D represenstaion of the 3D model. If I substitue modeling where you use rendering then what you say makes sense to me.

 

Sorry for the confusion. Terminology is always tough.

[TheKitchenAbode]

Agree Doug, I may have been a bit liberal with that term. It was intended to describe in general the process of taking the primary data such as vectors, textures, etc., (all those 1's & 0's) and performing whatever computations are necessary to build the image we see on our monitors. I have in my mind viewed this as the rendering process regardless of whether or not the rendered image is present in 2D or a 3D simulation. I guess one could argue that as we see the 3D image on a monitor that it is in reality a 2D image, there really is no depth (3rd dimension) capability in the monitors we use.

 

This probably won't resolve the terminology issue but hopefully it will help in interpreting my thoughts.

 

Many Thanks,

Graham

[Doug_Park]

No worries. Communication without misinterpretation is hard. I get myself into trouble frequently by using words that result in ambiguous meanings.

[CJSpud]

I would love to have a niche tool that allows us to place a "5-sided box" into a wall without knocking a hole out of the back layer of the wall (e.g. as we get with a wall opening).  Having the pass-through opening tool re-programmed to leave at least the outer layer on the back side of the wall would be a sweet feature to have in Chief.

 

In the meantime, Joe's solution is MUCH better than the procedures I used for two shower niches in a plan set I just finished and will work for me and save me time getting niches to look right for future projects.  If I had to show the framing in a wall with a niche in it, I can manually edit the framing to make it work for me until we get something better.