Rhino car modelling : The next audi TT

#61
Stage 13 : Lights


- Front lights :

I began with doing the black joint taht you can see on my renders. I simply used _Pipe on border edges, built the intersection curves between pipes and the light surface with _Intersect, trimmed these curves with eachother to have nice corners; finally split the surface with theses curves joinned together. I also "thickened" the surface, as you've done on body parts.



First give some thickness on the inside of the joint. Use the same tehcnic as for bodyparts (Normal line to the surface, then Sweep1 surfaces)



Now _Extrude the new border from the front view :



in this front view draw the line that will limit the turning indicator, and 2 circles for the spotlights.



Once you've made a copy of your lightglass surface, trim it with the previous line, the _Extrude and _Fillet :



Now we simply cap with a line (snap on surfaces end on the right and somewhere in the middle on the edge on the left) :



and with 2 _NetworkSrf. Ask for tangency for the second surface on the line we build before.



trim these 2 surface with the circles you drawn before, _Extrude and _Fillet :



Splotslights are simple geometry :

one filleted tube, torus, one trimmed sphere (with a circle) for the lens, and filleted cylinder (fillet radius = cylinder radius)







- rear lights :

First get the border of your surface (_DupBorder) and project it on the CPlane (use the _ProjectToCPlane in the rear view). Tell you d'ont want to keep the original curve :



for these kind of curve work, always project before you work on i. If not, curve fillet won't work...

Do a 0.3 _Offset inside the curve. Corners are screwed but we don't mind.



Draw now the curves that will limit different parts in the lights. Draw one curve each time.



use the offset commande again, will a 0.15 value. Use it twice for each curve, on each side



delete the first curves, then build fillets in the corners with the radius of your choice. You can choose to join curve while building fillets. (prompt option)



duplicate the light surface, move it a bit backwards "in" the car, and trim it with the curves we just built. _Extrude the borders :



in the side view, draw curves that fit the shpae you want to give to the inner reflective surfaces of the light. usually these surface are spherical or pseudo-cylindrical in order to reflect light coming from the center bulb.



Build some Sweep1 with these crosssections (build the rails in the top view)



trim these sufaces with the extruded surfaces. I also personnaly trimmed them with circles to put LEDs in it.



good luck !
 
#62
Stage 14 : Exporting 3ds/igs


While your modelling in Rhino or once everything finished, you'd surely like to render that all, but not necessarely with rhino.
I personnaly render my models with 3dsmax. Here is the way to export your rhino files into Max.
Rhino offers lots of exporting formats because he' s largely used by industrial designers all around the world.

We are going to learn how to go from Rhino into max using the 3ds format (mesh) or the igs format (nurbs). I personnaly use the 3ds now but i'll show you the good side of the igs export.

3ds Exporting :

In rhino, keep only the part you want to export. You should export each part alone, because the mesh preview is pretty long depending on the power of your computer. Moreover, parameters may change from one part to another. Finally, sometimes you don't want the same level of detail on all parts.

I picked the front fender :



right click on the Save Icon or choose Export in the File menu. A window appears, asking for a file name and for a format. Choose the 3ds format :



in the pop up that follows, click "Details controls"



Parameters are rhino defauls parameters (not on my pic !)


Maximum angle : maximum angle between 2 triangles

Maximum aspect ratio : maximum ratio between longer and shorter length of a triangle

Minimum edge length : Minimum edge length of a triangle

Maximum edge length : Maximum edge length of a triangle

Maximum distance, edge to surface : maximum distance between a triangle edge and the mathematical theorical nurbs surface

Maximum initial grid quads : size of the initial quad grill that Rhino put in each surface before mesher the seams.

other parameters are to be checked or not :

refine mesh : always check. allow the mesher to work properly on seams

jagged seams : do not check. if you check it, each surface is independantely meshed. Seams are off.

simple planes : do not check. ignore it.

weld : check or not. I never saw any difference in Max.

pack textures : do not check. ignore it.

Let's get back a bit on nurbs theory. Nurbs are mathematical objects. They can only be represented by small faces. So mesh is used. We you calculate a approximation of the surface by a mesh, we always do a Error. The smaller this error is, the better the mesh looks like the perfect surface. When the Error tends to zero, the mesh get dense and tends to the mathematical surface.
The Maximum distance, edge to surface represent this Error in a way. Think of the representation of a sphere in max. When you increase the number of faces, the sphere become more and more "round", and the distance between the faces and the perfect sphere decreases.
it works the same for nurbs surfaces. If rhino mesher were perfect, this parameter would be enough to mesh whatever the part you want. But you often have to play with the other to have something nice.
Try this :



click on Preview, wait and see the meshed surface :



you can move, pan, zoom to inspect the geometry

in some places, Rhino will do this kind of crappy mesh ( i never understood why because there is no surface variation here...)



to get rid of that, you can decrease the "Maximum distance, edge to surface" parameter, or play with the other ones. I often use the last one and put a value of 50 for example. Sometimes you 'll have to use the "Minimum edge length" to avoid the numerous little faces that Rhino like to create in some places...
Don't be scared of preview calcul time. it can be pretty long with complexe polysurfaces. Check the Prompt line to see how many faces you got.



depending on your goals, choose a maximum value for the numlber of faces. But whatever the face number, try to keep it under 65000. The problem is that Rhino counts quads as 1 face instead of 2 like max...
in 3ds files, maximum face count for a piece is 65536. if you go over this number, the part will be splitted into 2 parts, in a crappy way. So (and with the quad issue it's not easy) try to remain under the 50000 faces, which is already a big part. If not you will have more than 1 million face for the whole car, which is not really practical to work with afterwards.

Here is a nioce export re imported in max :



Apply a material with a non zero specular level to it to check it. Export it again in Rhino if you're not satisfied with it. Keep Rhino and Max opended and jump from one to another to find the perfect export parameters.

When you found the good parameters, you will notice this in all cases :



what were surfaces seams in Rhino is not welded in Max !

What you must not do : select all vertex and weld everything. You'll get some mess up areas because some triangle are deformed and cause shading problems.
What you must do : select the big sufaces in the volume sub-object mode, and Hide the other (Invert selection and Hide it). Select the regions of vertex you want to weld. Weld them using a small value, since they are exactly at the same place.



After that the surface should be ok. Good luck for the whole car...


Igs Exporting :

When exporting in Rhino, choose the igs format :



in the pop up, choose Details controls, then 3dsmax 5.0 in the first item. check that Iges tolerance is the same as your Rhino global tolerance, which is 0.01 if you havn't changed it.



Import in Max.



You have now nurbs objct in max. Check the modifier stack for sub objects :



in Surface sub object mode, you have this menu :



The mesher works a bit like theRhino mesher, but with few parameters only.
You'll notice there are two configurations : one for the viewport, adn the other for the Render
this is one advantage of the igs export, that allow light meshs in viewport to work easily and nice renders.

Don't change the parameters of the viewport configuration and switch to render configuration.
You have 3 presets. You can try the 3 ones and look a the difference when rendering.
You should see the difference when you zoom near to the surface.
Be aware that "low" in the render is already more accurate that the "high" in the viewport...

So even with the "High" preset in the render mode, you see holes between surfaces :
You have to increase the "Merge" parameter.

With the default 0.01, this is what i get



increasing now to 0.5 is better :



The problem with nurbs is that you don' treally control the number of faces you have.
One can see that here i've used 58000 face with the nurbs, whereas i only had 15000 in 3ds format.



I personnaly think that both technics are equivalent. Igs is faster to work wit but generate often heavy files. So if you have a powerful configuration, choose igs export. 3ds export is good because you control the mesh, but the export phase is pretty long, and the post work in max too...

for every question about this lesson or about the tutorial, email me. good luck. The Rain Knight 2005(c).

 

tyio

New Member
#63
eheh, thanks to make the last part ^^


maybe i can ask you some little thing here ??? (if not,i'll go into french section but don't receveid notification :( )



so, it's about scale and fillet edge command, always fail on my rhino, it's a pain to duplicate edge, and make a pipe (explose it, extend it.....) then make a blendsrf , the filletedges is very helpfull and i don't know why it's fail.... Maybe the scale of the model ???, and if not, do you have a solution ?




ps: export into obj format, it's better, and you can export part upper than 65kp ;)
 
#64
Great tutorial, thanks for doing it!

The funny thing is that I'm using exactly the same methods for every step desccribed. I always thought I invented the tricks all by myself :lol:
 
A

Anonymous

Guest
#66
end model looks amazing. i'm new to rhino and i can't work out which lines you mean and in which order :?

"Then use a _NetworkSrf with all the limiting curves and with the one is the middle too."
 
#67
Hi guest,

I think your having problems with creating the roof surface. Rain Knight is talking about the curves surrounding the roof you're going to make. The curve in the middle is the yellow one on the right which is made between the two sides of the roof surface you're building

Hope this helps
 
#68
tyio said:
eheh, thanks to make the last part ^^


maybe i can ask you some little thing here ??? (if not,i'll go into french section but don't receveid notification :( )



so, it's about scale and fillet edge command, always fail on my rhino, it's a pain to duplicate edge, and make a pipe (explose it, extend it.....) then make a blendsrf , the filletedges is very helpfull and i don't know why it's fail.... Maybe the scale of the model ???, and if not, do you have a solution ?




ps: export into obj format, it's better, and you can export part upper than 65kp ;)
hey tyio, you here :) !
check g3d for your french answer :) (i only got my internet connexion today :))
and thx for the.obj trick. will be very very usefull.
 
G

gre03

Guest
#69
ive finished the modeling, but i have two gaps in the car.
how do i fill them in or what do i do?
 
#74
i havent done this tutorial, but u can c clearly u've got proportion problems, thats y the wheel doesnt fit in, i think the roof should go lower, and the body higher (not including the roof), and increase wheel well size
 
#77
first off: after I've finished the model I'm doing right now, I'm going to try out this Rhino stuff, you really make it look easy! great tutorial man ;)

and for gre03, my guess it that you'll have to export it to 3d studio max and render it out there.