[code] Is there a way to know if cursor on top of shadow?

renderiza

Is there a way to know if cursor on top of shadow?

This might be useful for an idea I have. Also it will be cool to select only faces that have shadow.

thanks

Here is final answer thanks to TIG...


@@model = Sketchup.active_model ;

def onLButtonDown(flags,x,y,view)

   ip1 = view.inputpoint x,y ;
   point = ip1.position ;
   svec = @@model.shadow_info["SunDirection"] ;
   hit_path = Sketchup.active_model.raytest [point,svec]

   if hit_path

       UI.messagebox("On Shadow") ;
            
   end #if

end #def

TIG

Not directly...
BUT you could devise some convoluted way...
Use a model.raytest from your cursor's 'best picked point' using the sun.direction.reverse to determine its vector. Use the shadow-info to get data like that...
If the raytest returns nil there's nothing between the point and the sun [i.e. no shadow], BUT it it returns something else then the sun is casting a shadow on that point...

renderiza

Thanks TIG for the fast replay!

Your suggestion seems like the right way so I will try to make it work...again thanks!

TIG

If you do manage to get a working method perhaps you could share just that part of your new tool on the open forum ?

renderiza

@tig said:

If you do manage to get a working method perhaps you could share just that part of your new tool on the open forum ?

Hi, I am currently doing some little research before making the final code and I stumbled on a post you made that might be useful to understand.

Here is what you coded on this thread...http://sketchucation.com/forums/viewtopic.php?f=323&t=35887&start=0

@tig said:

model=Sketchup.active_model
svec=model.shadow_info["SunDirection"]
peye=model.active_view.camera.eye
clin=model.active_entities.add_cline(peye, svec)
clin.end=nil
clin.start=peye

Of course if I am able to make working code I will share it with forum.

By the way the basic idea for this was to add a feature to a plugin I am making called "Canvas" where you make a group or component plane that has material opacity to about 5% and this will allow you to "paint" groups or comp to only faces that have shadow on them.

But thinking of others ideas on how else this can be useful is fun...cheers!

renderiza

WIP

Hi, here is a what I have done so far...


@@model = Sketchup.active_model ;

def onLButtonDown(flags,x,y,view)

   ip1 = view.inputpoint x,y ;
   point = ip1.position ;
   svec = @@model.shadow_info["SunDirection"] ;
   peye = @@model.active_view.camera.eye ;
   clin = @@model.active_entities.add_cline(point, svec) ;

   clin.end = peye ;
   clin.start = point ;

end #def

I started with add_cline to test but soon I will add the model.raytest to evaluate if it returns nill or not.

Again thanks and will keep you posted on the progress

Note: Here is the Canvas Plugin just in case someone is interested...
http://sketchucation.com/forums/viewtopic.php?f=323&t=51655

renderiza

Here is the final code to detect if the cursor is on a shadow...

@@model = Sketchup.active_model ;

def onLButtonDown(flags,x,y,view)

   ip1 = view.inputpoint x,y ;
   point = ip1.position ;
   svec = @@model.shadow_info["SunDirection"] ;
   hit_path = Sketchup.active_model.raytest [point,svec] 

   if hit_path != nil

       UI.messagebox("On Shadow") ;
				
   end #if

end #def

Thanks TIG!

thomthom

Is sun direction pointing to the sun? Not from the sun?

Btw, no need to compare against nil. ( != nil or == nil )

if hit_path != nil

is the same as

if hit_path

If you want to check if an value is nil - then you can use .nil?

TIG

The 'SunDirection' gives something like:
Vector3d(-0.424437, -0.772256, 0.47273)
When the sun is 'in the south' so that suggests the returned vector is towards the sun.
Otherwise its Z would be negative - i.e. downwards ??

thomthom

True that. Just didn't expect it.

renderiza

Thanks thomthom for pointing out that "!= nil" was not needed.

cheers!

Dan Rathbun

... because in a boolean expression nil (and false,) eval falsely.

Everything else including true, [] (an empty array), and 0 (the integer zero,) evaluate truthfully.