Scaling down scene meshes/elements Pros and Cons?

Blitz3D Forums/Blitz3D Beginners Area/Scaling down scene meshes/elements Pros and Cons?

RustyKristi(Posted 2016) [#1]
I've been around for some time and seen a lot of examples and one thing I noticed is that most of them are scaled down. So pros and cons?

How can I use same position/rotation integer values as the not scaled down version?


RemiD(Posted 2016) [#2]
For non rigged non skinned meshes i use scalemesh. (it repositions the vertices)
For rigged skinned meshes i use scaleentity. (it scales down the root joint/bone)

The reason i do that is because it is easier to modelize in Fragmotion with 1unit=1cm, so then i have to scale down my meshes by 100...


RustyKristi(Posted 2016) [#3]
Thanks RemiD. So is it better to scale down entities/scene on B3D?


RemiD(Posted 2016) [#4]
no, it depends on the scale you prefer to work with in your modeling software.


RustyKristi(Posted 2016) [#5]
ok thanks.


gpete(Posted 2016) [#6]
just for fun I have a program that loads all the meshes I have made and places them on a grassy plane. It is interesting to see what size the different modeling programs create objects- some various 3D modeling program I have used are- Silo, Shade 8, Metasequoia, DeleD, Sculptris, Wings 3D and Curvy 3D, Sketch-up Make(free version-now has exporting OBJ files!). I have even found using Open Sim useful in modeling- (some of my most detailed items have been made in Open Sim- you can export DAE and OBJ files).


Matty(Posted 2016) [#7]
When I used to use softimage XSI the units were such that 1 softimage unit = 1 blitz unit...I didn't scale anything....scaling is just that, scaling, as long as everything is consistent size visually for the user scaling doesn't matter..admittedly purchased models often have different sizes....if I were doing a game where it was mostly about human beings however with a very tiny playing field i would probably use 1 blitz unit = 1 cm, but typically I aim for 1 blitz unit = 1 m in the real world.


RemiD(Posted 2016) [#8]
If you can it is better to use 1unit = 1meter but some modeling tools (like Fragmotion or 3DWS) are easier to use with a different base unit (depending on the minimum/maximum grid size and depending on the camera turn/move/minrange/maxrange and depending on the minimum/maximum step when you rotate/position a vertex/shape). So then you will have to scale down the mesh when you import it in Blitz3d...


Bobysait(Posted 2016) [#9]
It all depends on your program scale.
If it's a space opera, maybe even the 1 unit=1 meter will make large precision loss (big spaceship of undreds of meters)
But if it include people with "real" size, things get more complex.

Anytime you scale things in blitz3d or in your modelisation software, it just lower the precision of the internal transformation matrix.
So, you end with rotation that don't give the exact pitch yaw or roll, and eventually a position that can't be offseted by a single centimeter without adding extra millimeters, so nothing can be accurate.

There is no reason to use a specific unit against another, but in any case, it's really better to have your models at the same unit size as your program (whatever this unit is).

By the way, there used to be some functions that doesn't care about the scale, so they become unusable if not tweaked (and it's not always easy to do), like EntityBox or EntityRadius.
And it's already not simple to have a good range for the camera to prevent z-fighting , so using random scales will just make it worst.